Frequently Asked Acne Questions

Frequently Asked Acne Questions

There are many claims about what causes acne and what treatments are effective for improving acne symptoms. Some of these claims are entirely true, some are partially true, and many are completely false. There is also a tremendous amount of contradictory information about acne available from lots of different sources.

In this FAQs section we address the most common acne-related questions on topics such as diet, hygiene, bacteria, hormones and more. For in-depth discussions the scientific aspects of acne, refer to our Acne Science page.

What is Acne?

Type 3 Acne on Forehead
Type 3 Acne on Forehead

Acne is a difficult to treat and often debilitating disease that affects the skin, usually the face. The most common form of acne (acne vulgaris) is an infection within a hair follicle. This infection causes varying degrees of inflammation, which manifest as pimples, nodules and cysts. When the inflammation is severe, it can cause permanent damage to the skin and create acne scars. This section covers the basics of what acne is and the different types of acne.

What Causes Acne?

Inflammatory Acne Papules Skin and Cellular View
Inflammatory Acne Papules Skin and Cellular View

Acne is a complex disease and many factors can contribute to the development of acne symptoms. Every case of acne is unique and the blend of factors that cause acne varies between individuals. This section contains a list and discussion about the factors that are major contributors to the development of acne symptoms.

What is the Best Acne Treatment for Me?

Over The Counter (OTC) Acne Products
Over The Counter (OTC) Acne Products

Choosing the best acne treatment(s) for each individual depends on many factors. The type and severity of your acne, your age, gender, treatment history and personal preferences are all important. If possible, you should work with your dermatologist or healthcare provider to develop a comprehensive acne treatment plan that is specifically tailored to your needs. Treatments for active acne and acne scars can be roughly divided into 6 different categories: Over The Counter (OTC) Treatments, Pharmaceutical (Rx) Treatments, Naturopathic/Homeopathic Treatments, Light & Laser Treatments, Surgical Treatments and Acne Scar Treatments. This section contains detailed information about all of the available acne treatments.

What are the Different Types of Acne Scars?

Rolling Acne Scars on Face (Woo)
Rolling Acne Scars on Face (Woo)

Acne scars come in many different shapes, sizes and even colors. Each type of acne scar has its own unique characteristics and features. Because of these differences, the available treatments for acne scars are not one size fits all. It is important to carefully choose the treatment that best matches your needs in order to achieve optimal results. Acne scars can be classified into three main groups: Depressed (pitted scars), Raised (keloid scars) and Discoloration scars. This section discusses the different types of acne scars and the features that define each group.

How Do Acne Scars Form?

Ice Pick Acne Scars on Cheek
Icepick Acne Scars on Cheek

Acne scars are the result of tissue damage caused by inflammatory acne. The vast majority of acne scars are caused by from persistent cases of inflammatory acne affecting the same area of skin. Individuals who suffer from frequent nodular and cystic acne outbreaks (Acne Types: 3-4) are at a very high risk of developing permanent acne scarring. This is particularly true when a region is affected by overlapping acne outbreaks, with no opportunity for the skin to completely heal between outbreaks. This section discusses the different factors that contribute to the development of acne scars.

Is acne caused by dirt or not washing my face enough?

Facial Cleansers are Popular OTC Acne Products
Facial Cleansers are Popular OTC Acne Products

The answer is usually NO. In most acne lesions (pimples, nodules, cysts, etc.), the site where the infection and inflammation is centered is not near the surface of the skin. Instead, it is near the base of the hair follicle where the sebaceous gland attaches. This is a region of the follicle that is not readily accessible from the surface. Therefore, cleansers and their active ingredients are unlikely to impact the inflammatory processes that drive moderate to severe acne symptoms (Acne Types: 2-4). This section discusses the benefits, risks and uses of acne facial cleansers.

Is Popping a Pimple a Bad Idea?

Popping a Pimple
Popping a Pimple

The answer is that it can be, especially if done improperly. Some pimples and other acne lesions benefit from being drained or popped in order to remove pus and accelerate healing, but other pimples should be left alone to heal on their own. The nodules and cysts of those patients who suffer from severe inflammatory acne (Acne Type: 4) are often lanced and drained by a dermatologist. This can prevent further damage and limit post-acne scarring. The important thing is to identify those zits and pimples which can be effectively popped (and which ones can not), and to do that properly and in a sterile fashion. This section discusses the risks, benefits and techniques for draining acne lesions.

Does Greasy Food, Milk or Chocolate Cause Acne?

Does Pizza Cause Acne?
Does Pizza Cause Acne?

The answer is probably not. Anecdotal associations between acne and particular foods like chocolate, ice cream and pizza have largely been discredited by scientific research. But research does point to a connection between overall diet and the development of acne symptoms. Researchers have shown that people whose diets include lots of high glycemic index foods (foods that are high in sugar and simple carbohydrates) tend to experience acne at a greater frequency than those who have low glycemic index diets. However, there is no clear scientific consensus on why this connection exists. This section discusses several of common claims about the association of specific types of food and acne symptoms.

What Does Non-Comedogenic Mean?

Acne Patients Should Avoid Comedogenic Substances
Acne Patients Should Avoid Comedogenic Substances

Comedogenicity refers to the potential of a substance to cause a comedo, a plugged or inflamed pore. Non-comedogenic means that in testing, the substance or product has not been shown to cause comedos (clogged or inflamed hair follicle). Some substances (eg. coal tar) are highly comedogenic and produce a type of allergic, acne-like reaction. There is not a clear consensus when it comes to the comedogenicity of many substances, with different tests yielding different results. This section discusses what comedogenicity is, how it is tested and which products and substances are likely to be comedogenic.

Can Stress Cause Acne?

Stressed Out
Stress

Stress can inhibit the function of the immune system and trigger or worsen acne symptoms It is well known that putting an organism under stress makes it more susceptible to infection. This is true for humans, animals and even plants. The same neural and biochemical pathways that make stress feel uncomfortable can also disrupt the delicate balance of a properly functioning immune system. This section discusses the relationship between stress and the development of acne symptoms.

What is the Relationship Between Acne, Depression and Suicide

Diagram of Psychological Impact of Acne (Magin)
Diagram of Psychological Impact of Acne (Magin)

Acne can have a profound negative impact on the psychological well-being of acne sufferers. Acne can increase the risk of bullying, depression and suicide.
For the millions of people who have suffered with acne, the psychological toll of the disease is well understood. The face is the window that connects one’s consciousness with the outside world. The face is also an essential factor in how the outside world perceives an individual. More than any other part of the body, diseases that affect the appearance of the face can have severe emotional and psychological consequences. This section discusses the connections between acne, stress, depression and suicide.

Is Acne Different Between Men and Women?

Acne Tends to be Different Between Men and Women
Acne Tends to be Different Between Men and Women

Yes, and it mostly comes down to hormones. Men and women tend to experience acne differently. Men are more likely to develop acne during puberty and are more likely to develop severe and inflammatory forms of the disease. Acne symptoms tend to peak during adolescence and recede during a male’s mid 20’s. In contrast, women tend to experience less acne and less severe acne than men, but rates of acne actually increase for women in the 20-40 age range. This section discusses key differences in acne symptoms between men and women, and why these differences exist.

What is the Relationship Between Pregnancy and Acne?

Pregnancy can Trigger Acne Symptoms in Some Women
Pregnancy can Trigger Acne Symptoms in Some Women

There are a tremendous number of changes that take place in the female body during pregnancy and these changes can have both positive and negative effects on acne symptoms.
Many women experience dramatic changes in their acne both during and after pregnancy. Hormones that control the natural processes of menstruation and pregnancy have wide ranging effects throughout the body. Onset of acne or a worsening of acne symptoms is very common during pregnancy. At the same time, a smaller percentage of women report an improvement in their acne symptoms during pregnancy. This section discusses the effects that pregnancy can have on acne symptoms.

Anabolic Steroids and Acne

Arnold Used Lots of Anabolic Steroids
Arnold Used Lots of Anabolic Steroids

Anabolic Steroids (aka Roids, Juice, AAS, etc) are molecules that mimic the shape and function of androgen hormones (eg. Testosterone). Anabolic Steroids are generally used to stimulate protein synthesis and muscle growth. They are widely used as performance enhancing drugs (PEDs) in athletics. Anabolic steroids should not be confused with corticosteroids, which are immune suppressants and can actually inhibit muscle growth. Corticosteroid injections are sometimes used to treat acute inflammation in severe acne lesions. Anabolic Steroids are never used as an acne treatment, and their use can cause or worsen acne symptoms. This section discusses the biology of anabolic steroids and their role in the development of acne symptoms.

What is Propionibacterium acnes?

Propionibacterium acnes (Toyoda, et al)
Propionibacterium acnes (Toyoda, et al)

Propionibacterium acnes (P.acnes) is a bacteria that can colonize the the skin and hair follicles. Excessive growth of this bacteria in the skin contributes to acne vulgaris. Propionibacterium acnes (P. acnes) is a bacteria that grows deep inside of pores, where it feeds on the sebum that is produced by the sebaceous glands that surround the base of the hair shaft. Most individuals with acne symptoms have an overgrowth of P. acnes bacteria in their skin. Several research studies have indicated that specific strains of P. acnes bacteria are commonly associated with acne vulgaris. This section details what P. acnes bacteria are and how it contributes to acne symptoms.

Is acne caused by dirt or not washing my face enough?

Facial Cleansers are Popular OTC Acne Products

Answer: Not really.

Topical facial cleansers are generally ineffective treatments for all but the most mild cases of acne (Acne Type: 1). Medicated and non-medicated acne washes are widely available in grocery, drug and department stores as Over The Counter (OTC) products.

In most acne lesions (pimples, nodules, cysts, etc.), the site where the infection and inflammation is centered is not near the surface of the skin. Instead, it is near the base of the hair follicle where the sebaceous gland attaches. This is a region of the follicle that is not readily accessible from the surface. Therefore, cleansers and their active ingredients are unlikely to impact the inflammatory processes that drive moderate to severe acne symptoms (Acne Types: 2-4).

Topical Face Wash Acne Cleansers
Topical Face Wash Acne Cleansers

Commercials for acne cleansers often have animations that show their product blasting out the debris from deep within pores (follicles). In reality, this does not really happen because the follicle shaft is quite narrow relative to its depth. In addition, individuals with acne often have sticky “hyper-keratinized” plugs that are firmly lodged in the follicle. These plugs prevent surface-applied treatments from reaching the interior of the follicle. The inside of the follicle is mostly an anaerobic environment (low levels of oxygen). The interior of the follicle has a different composition of resident bacteria than the surface of the skin.

The plugs that clog follicles and contribute to acne do not usually come from dirt or grime on the surface of the skin. Rather these pore-clogging plugs come from sebum, keratin and cell debris which is all produced deep within the follicle. Sebum is a natural product of the sebaceous glands and is responsible for lubricating and protecting healthy skin.

Propionibacterium acnes (Toyoda, et al)
Propionibacterium acnes (Toyoda, et al)

It is important to recognize, however, that foreign debris and bacteria on the surface of the skin can aggravate acne symptoms. This is especially true if you pop a pimple or damage the skin, which allows surface debris and bacteria to enter the open wound. This can potentially cause increased inflammation and even a secondary infection, both of which can exacerbate existing acne symptoms.

Cleansers and Acne: The Positives

Salicylic Acid Cleanser Wash (Neutrogena)
Salicylic Acid Cleanser Wash (Neutrogena)

Twice daily use of non-medicated gentle facial cleansers was shown to decrease the number of open-comedos (blackheads) in a small study. However, non-medicated cleansers had no measurable effect on closed comedos and inflammatory acne (whiteheads, nodules, cysts). This is most likely due to the concept mentioned above, that the plug blocking the follicle is not easily accessible from the surface in closed comedo and inflammatory acne lesions.

In the case of a blackhead (open-comedo), the plug is very near the surface of the skin, and is therefore more susceptible to to the action of cleansers. Another study by the same research group showed that a medicated cleanser that contained Triclosan, Salicylic Acid and Azelaic Acid (antibacterial and keratolytic agents) was capable of decreasing the number of acne lesions when compared to a non-medicated control.

Salicylic Acid Cleanser Pads (AcneFree)
Salicylic Acid Cleanser Pads (AcneFree)

Triclosan, Salicylic Acid and Benzoyl Peroxide are common ingredients in Over The Counter (OTC) acne treatments. The available research indicates that when cleansers are used in moderation they can be helpful in reducing minor acne symptoms for some patients.

It is important to note that most of the OTC medications have the same ingredients, and many acne sufferers use several of these products at the same time. This can easily lead to excessive use of this class of acne product. The most common result of overuse of these products is dry and irritated skin. The positive effects of keratolytic agents and mild anti-bacterial compounds like triclosan are not cumulative and excessive use is likely to lead to more damage than benefit.

Cleansers and Acne: The Negatives

The primary concern associated with acne face and body washes is overuse. When you have acne, you want to do something about it. That’s a natural response, but all too often that desire to act translates into an over-kill approach, like excessive face washing. Most of the research studies on acne and acne facial/body cleanses found that using these products more than twice a day causes more harm than benefit.

Excessive use of acne washes can leave your skin dry, cracked and irritated.
Excessive use of acne washes can leave your skin dry, cracked and irritated.

Excessive use of cleansers or other abrasive products the skin is likely to aggravate acne symptoms. Excessive washing or use of harsh products can damage and irritate the skin, leading to cracking, redness, inflammation, discomfort and ultimately worsen acne symptoms. The general rule of thumb is to use gentle cleanser in moderation to keep the skin clean. Washing the skin more than that is unlikely to provide much benefit and is more likely to make symptoms worse.

It is also important to limit your expectations for how helpful cleansers and face washing are going to be for your acne. Keep in mind that even the studies that show that cleansers help acne are only talking about moderate improvements for people with mild acne.

Overall, the consensus of scientific research does not suggest that cleansers help moderate to severe inflammatory acne. At no point do any of these research results indicate that cleansers can “cure” acne. At best, cleansers can only be expected to marginally improve acne symptoms.

References and Sources

How to Wash Your Face: America’s Leading Dermatologist Reveals the Essential Secrets for Youthful, Radiant Skin. Kenet, et al. 2002.
A Consumer’s Dictionary of Cosmetic Ingredients, 7th Edition: Complete Information About the Harmful and Desirable Ingredients Found in Cosmetics and Cosmeceuticals. Winter. 2009.
Acne Vulgaris. Shalita, et al. 2011.
A systematic review of the evidence for myths and misconceptions in acne management: diet, face-washing and sunlight. Magin, et al. 2004.
A Single-Blinded, Randomized, Controlled Clinical Trial Evaluating the Effect of Face Washing on Acne Vulgaris. Choi, et al. 2006.
A study of the efficacy of cleansers for acne vulgaris. Choi, et al. 2010.

Is Acne Different Between Men and Women?

Acne Tends to be Different Between Men and Women

Yes, and it mostly comes down to hormones.

Men and women tend to experience acne differently. Men are more likely to develop acne during puberty and are more likely to develop severe and inflammatory forms of the disease. Acne symptoms tend to peak during adolescence and recede during a male’s mid 20’s. In contrast, women tend to experience less acne and less severe acne than men, but rates of acne actually increase for women in the 20-40 age range. Many women who have never had complexion problems begin to experience acne symptoms during pregnancy, and sometimes acne continues to persist after completion of the pregnancy.

Androgens Drive Muscle Growth
Androgen Hormones Drive Muscle and Body Hair Growth

While there are many contributing factors to acne, the main differences between men and women can be traced to hormones. Men, particularly adolescent males, tend to have elevated levels of male hormones called androgens. Androgens include hormones like testosterone. Among other things, androgens stimulate the growth of sebaceous glands, which increases the amount of sebum produced by the skin. Increased sebum production fosters the growth of bacteria that feed on sebum, such as Propionibacterium acnes. Additionally, high levels of sebum production can increase the incidence of clogged pores that block the opening of the hair follicle and encourage the development of acne symptoms like pimples, nodules and cysts.

Androgen Inhibitors and Acne

Finasteride 5mg Tablets (Fincar)
Finasteride is an Androgen Inhibitor

Androgen Inhibitors are a class of medication designed to block the function of endogenous androgens. Androgen Inhibitors are commonly used in women to treat elevated androgen levels, which can lead to hirsutism (excess hair growth) and masculinization. They are also used in men to treat male pattern baldness and certain kinds of cancer.

Androgen Inhibitors can be an effective treatment for women who experience androgen-dependent acne. Androgen inhibitors have a feminizing effect on men and are generally not recommended for use in males. Androgen inhibitors are often used as part of the hormone therapy involved in male to female sex change operations.

References

Correlation Between Serum Levels of Insulin-like Growth Factor 1, Dehydroepiandrosterone Sulfate, and Dihydrotestosterone and Acne Lesion Counts in Adult Women. Cappel, et al. 2005.
Acne in Victorian adolescents: Associations with age, gender, puberty and psychiatric symptoms. Kilkenny, et al. 1997.
Post-adolescent acne: a review of clinical features. Goulden, et al. 1997.
Prevalence of facial acne in adults. Goulden, et al. 1999.

Is Popping a Pimple a Bad Idea?

Whitehead Pimple

Answer: It can be, especially if done improperly.

Popping a Pimple
Popping a Pimple

Some pimples and other acne lesions benefit from being drained or popped in order to remove pus and accelerate healing, but other pimples should be left alone to heal on their own. The nodules and cysts of those patients who suffer from severe inflammatory acne (Acne Type: 4) are often lanced and drained by a dermatologist. This can prevent further damage and limit post-acne scarring.

The important thing is to identify those zits and pimples which can be effectively popped (and which ones can not), and to do that properly and in a sterile fashion. Although it can be tempting to try and pop all zits pimples, in many cases it is more effective to allow the natural progression of the lesion and healing process to take place.

Benefits of Popping a Pimple

Whitehead Pimple Skin and Cellular View
Whitehead Pimple Skin and Cellular View

In some cases, it can be beneficial to extract the pus from inside of a pimple. Pus (the white stuff, not the clear fluid) is composed largely of specialized white blood cells called Neutrophils. These white blood cells migrate to the site of infection (the zit) and are designed to destroy and phagocytose (eat) the offending bacteria and other foreign material. These white blood cells are most apparent in open comedome lesions (whitehead pimples).

After accumulating in an acne lesion, the white blood cells release powerful enzymes and free radicals that are designed to kill and digest the source of infection. Unfortunately, these weapons also cause collateral damage to the healthy tissue around the infected follicle. In people who suffer from inflammatory acne, it is often an overeager immune response that causes swelling, redness and discomfort. The collateral damage to healthy tissue during this process is what causes the formation of acne scars.

In acne lesions that are significantly inflamed but easy to drain, removing the pus can limit the amount of collateral damage that occurs and can accelerate the healing process. In addition, the infiltration of the follicle with pus can put a lot of pressure on the surrounding nerves, which can be quite uncomfortable and painful. Draining a lesion may be helpful in relieving this pressure and the accompanying discomfort.

Risks of Popping a Pimple

Corticosteroid Injection into Acne Cyst
This Acne Cyst Requires Surgical Extraction

Many acne lesions (especially nodular and cystic acne lesions) can be very difficult to effectively pop and drain. Small, non-inflammatory acne lesions (Acne Types: 1-2) may not contain significant pus that can be drained. In these cases, attempting to drain the lesion can be unhelpful or cause further damage that slows down the healing process and contributes to more acne scarring.

In many acne pimples and cysts it is not just that the follicle is swollen with white blood cells and edema fluid, but rather the entire region of skin tissue is affected. Channels can form in the sub-cutaneous tissue and these channels can be occupied by bacteria laden white blood cells. Non-productive squeezing of pimples in these cases can force these white blood cells (and bacteria) away from the pimple and into the surrounding tissue. This can further spread the underlying infection and inflammation.

Aggressive squeezing of pimples can cause additional damage to the follicle itself, which leads to more inflammation and extends the amount of time it takes for the damage to be repaired. Lancing or popping an acne lesion in a non-sterile fashion can introduce bacteria or foreign material that can lead to more inflammation or even a secondary infection.

In conclusion, there are a lot of things that can go wrong when popping a pimple. Most of these are related to improperly draining a lesion or attempting to drain an unsuitable lesion, or non-sterile technique.

Considerations for Popping a Pimple

Sterility

Neosporin Ointment
Neosporin Ointment

It is very important to sterilize the area to be treated both before and after attempting to extract a blackhead or drain a pimple. This includes thoroughly washing your hands, cleaning the treated area and swabbing the lesion with alcohol or medicated wipe before and after extraction/draining. Topical application of Neosporin can also be used to limit the chances of secondary infection and accelerate healing.

Selecting Appropriate Pimples

It is going to do more harm than good if you try to pop a pimple that is not ready or is not suitable for draining. For example, many whiteheads are good candidates for drainage because the infiltrate (pus) is pooled near the surface. However, many inflammatory acne lesions, like nodules and cysts are poor candidates for drainage because there is no easy way for the infiiltrate to reach the surface.

In acne lesions where you have inflamed red bumps, like nodules and cysts, the infiltrate is fairly deep under the surface of the skin, with no clear exit pathway. In these cases of inflammatory acne, the entire length of follicle above the epicenter of the lesion is likely to be inflamed, and basically swollen shut. Attempting to squeeze or drain these type of lesions often forces the infiltrate (which contains many inflammatory factors) down and out, into the surrounding tissue. This will most likely aggravate the situation, causing more inflammation, scarring and a lengthier healing process.

In general, to effectively drain an inflammatory acne cyst or nodule, they often must be surgically lanced, which is a procedure best done in a dermatology clinic.

Proper Technique

Whitehead Removal with Comedome Extractor
Whitehead Removal with Comedome Extractor

To extract a blackhead, or drain a whitehead, it is important to use good technique. This means applying gentle pressure in a manner that forces the plug or infiltrate up and out. To do this you need to try and get under the main pocket of the lesion and gently work it out. It is important to use gentle rolling pressure.

Vigorous squeezing and applying lots of pressure are much more likely to cause additional damage and aggravate the acne lesion. There are several manual “extractors” used to extract blackheads. These generally have a small ring that fits around the blackhead and are designed to apply even pressure around the follicle. However, research studies into these blackhead extractions show that they produce, at best, a mild improvement compared to doing nothing.

Some dermatologists use a machine that extracts hyperkeratinic plugs and other follicle plugs using a suction based extraction machine. For the casual, at-home user, pore strips offer a means to extract some easily accessible blackheads, but pore strips are not suitable for inflamed lesions (eg. whitehead pimples).

Example Technique

How Do Acne Scars Form?

Boxcar Atrophic Acne Scars on Cheek

Acne scars are the result of tissue damage caused by inflammatory acne.

How Do Acne Scars Form?

Type 4 Acne on Face
Type 4 Acne is Likely to Cause Acne Scars

The vast majority of acne scars are caused by from persistent cases of inflammatory acne affecting the same area of skin. Individuals who suffer from frequent nodular and cystic acne outbreaks (Acne Types: 3-4) are at a very high risk of developing permanent acne scarring. This is particularly true when a region is affected by overlapping acne outbreaks, with no opportunity for the skin to completely heal between outbreaks.

Progression to Inflammatory Acne and Tissue Damage
Progression to Inflammatory Acne and Tissue Damage

When an individual experiences persistent outbreaks of severe inflammatory acne, significant regions of the affected skin and underlying tissue can be damaged. Acne is an inflammatory process that usually involves an infection caused by bacteria (eg. Propionibacterium acnes). The inflammation that occurs during  severe acne prevents the body from mobilizing the cells and materials necessary for the normal healing process that is required to repair the skin. In this situation, the original (healthy) tissue can be replaced by fibrous scar tissue.

The Role of Inflammation in Acne Scarring

What many people may not realize is that acne scarring is primarily due to the body’s own immune response to infection, and not the infection itself. A major component of inflammatory acne is the migration of white blood cells to the hair follicle, sebaceous glands and surrounding tissue. These white blood cells compose much of the “pus” that comes out when you pop a zit.

White Blood Cells
White Blood Cells

The white blood cells that make up the pus in acne pimples, nodules and cysts are not uniform. Instead the pus contains a mixture of many different sub-types of white blood cells, such as macrophages, neutrophils, dendritic cells, T cells, granulocytes, mast cells and others. Neutrophils are one of the body’s front-line defenses against infection and these cells are usually the most abundant white blood cells in an acne lesion.

Many of the white blood cells (and especially neutrophils) produce powerful degradative enzymes that can damage health tissue. These cells also produce inflammatory molecules, super-oxides and free radicals. These weapons are designed to help neutralize pathogens and foreign invaders, but they can also cause damage to the surrounding healthy tissue. In inflammatory acne, the damage caused by these white blood cells can actually cause the underlying bacterial infection to spread, leading to more inflammation and tissue damage. This can create a vicious, self-fulfilling cycle of tissue damage that leads to permanent acne scars.

Infected and Inflamed Hair Follicle (Honcharu)
Infected and Inflamed Hair Follicle (Honcharu)

When it comes to scarring, perhaps the most important type of white blood cell is the neutrophil. The neutrophil is one of the first responders to the infected follicle, and can accumulate in great numbers. Neutrophils are kind of like the suicide bombers of the cellular world. When they reach the site of infection they can undergo apoptosis (controlled suicide) and degranulation, which releases many anti-microbial molecules, DNA and proteases into environment. These proteases that can cause tremendous damage to the surrounding tissue, which ultimately results in scarring. These proteases digest the elastin and collagen matrix that provides support and elasticity to the skin.

Health skin is supported by a complex matrix (scaffolding) that provides structural support and nutrients to the skin surface. When skin is damaged, this matrix helps guide the healing process. Without this matrix to guide healing, the body has a very difficult time properly repairing and re-creating the damaged tissue. In cases of persistent infection and inflammation, the body is not able to repair the matrix fast enough to keep up with the damage. In these cases, the body begins to build scar tissue, which is simple and tough. The scar tissue can permanently replace the more complex and delicate healthy matrix. This process underlies not only the formation of acne scars, but of other diseases marked by chronic inflammation, such as chronic obstructive pulmonary disorder (emphysema) and rheumatoid arthritis.

The Structure of Scar Tissue

Normal Collagen Matrix - Stained Blue (Lee)
Normal Collagen Matrix – Stained Blue (Lee)

Scar tissue is composed largely of collagen, which is the same material that comprises much of a healthy sub-cutaneous matrix. However, unlike the healthy matrix – which is a complex, spacious and interconnected web of collagen and other proteins – the collagen in scar tissue is much different. In scar tissue, the collagen becomes tightly bundled and tends to line up in a single direction, instead of the original, interconnected web pattern.

In scar tissue there is much less open space than healthy tissue, and many of the essential accessory proteins and molecules that are essential for the maintenance of healthy skin are absent. This alignment of the collagen fibers and their closely packed arrangement creates a denser, less elastic tissue. In addition, scar tissue becomes impermeable to migration by many cell types, preventing the formation of blood vessels and a regrowth of complex structures, such as hair follicles and sweat glands. This is why scar tissue is generally monotone, feels tough and dense to the touch, and is hairless. It also explains why the body has such a difficult time replacing scar tissue with healthy tissue.

Repairing Scar Tissue

Once scar tissue has been generated at a site of injury, it is relatively permanent without medical intervention. In some cases, the body will gradually replace some scar tissue with the healthy tissue, but this process is so slow that is largely irrelevant. The single best treatment for acne scarring, is to prevent it in the first place. This means aggressively attacking the infection and treating the inflammation as it arises.

Complete C02 Laser Resurfacing of Acne Scars
Complete C02 Laser Resurfacing of Acne Scars

Fortunately, there are many different treatments available to help repair acne scar damage. The ideal type of treatment is largely dependent on the specific types of acne scarring. Acne scar treatment generally involves either surgically removing the scar tissue, or breaking it apart with laser, heat or surgical treatments. Light and Laser treatments can be very effective treatments for many different kinds of acne scars. Invasive and non-invasive surgical treatments can also be very helpful. Topical Retinoids may also be helpful for very mild acne scars and uneven skin tone.

References

Physiopathology of acne vulgaris: recent data, new understanding of the treatments. Pawin, et al. 2004.
Topical ALA Photodynamic Therapy for the Treatment of Acne Vulgaris. Hongcharu, et al. 2000.
Human b Defensin-1 and -2 Expression in Human Pilosebaceous Units: Upregulation in Acne Vulgaris Lesions. Chronnell, et al. 2001.
A prospective, randomized, placebo-controlled, double-blinded, and split-face clinical study on LED phototherapy for skin rejuvenation: Clinical, profilometric, histologic, ultrastructural, and biochemical evaluations and comparison of three different treatment settings. Lee, et al. 2007.

Acne, Depression and Suicide

Type 2-3 Acne on Chin

Acne can have a significant negative impact on the psychological well-being of acne sufferers. Acne can increase the risk of bullying, depression and suicide.

For the millions of people who have suffered with acne, the psychological toll of the disease is well understood. The face is the window that connects one’s consciousness with the outside world. The face is also an essential factor in how the outside world perceives an individual. More than any other part of the body, diseases that affect the appearance of the face can have severe emotional and psychological consequences.

Diagram of Psychological Impact of Acne (Magin)
Diagram of Psychological Impact of Acne (Magin)

Scientific research overwhelmingly demonstrates the negative effect that acne has on the quality of life of individuals with acne. Research has consistently shown that severe acne increases the incidence of depression, anxiety, bullying and suicide. Acne, especially severe acne (Acne Types: 3-4), can dramatically alter how an individual interacts with others and how they perceive themselves.

Despite these the profound impact acne can have on people, acne-free individuals often underestimate the impact that acne can have on self esteem and overall mental health. This phenomenon can leave acne sufferers feeling very alone. To better understand the psychological toll that acne can have (and to let people know that they aren’t alone), we have synthesized the data from many studies into four basic categories.

Acne, Anxiety and Depression

For acne sufferers, it is virtually impossible to escape the constant reminders of the disease. Every reflection in the mirror becomes a depressing reality check, and the physical pain associated with inflammatory acne makes it’s presence inescapable. For many acne sufferers, dealing with acne and acne scarring is extremely challenging, both mentally and physically.

Incidence of Psychological Issues in Acne Patients (Dalgard)
Incidence of Psychological Issues in Acne Patients (Dalgard)

Virtually every study conducted on the psychological impact of acne vulgaris has shown that the disease causes a statistically significant increase in anxiety, depression and related mental health problems. On balance, the research indicates that rates of anxiety and depression among individuals with significant acne symptoms are about double those of non-acne sufferers. Acne also causes significant increases in rates of body dysmorphia, anti-social behavior and suicide.

The psychological impact of acne is not all in the mind of the person with acne. Research indicates that children and adolescents that suffer from acne and other skin diseases, experience increased levels of bullying and teasing. Too often this psychological trauma is overlooked or dismissed by parents, physicians and other decision makers. As a result, acne sufferers often fail to get the psychological and psychiatric treatment that they need.

Research shows that the level of anxiety and depression is directly related to the severity of acne symptoms (which seems like an obvious conclusion). Fortunately, improving acne symptoms through effective treatment also improves many of these psychological problems. Effective treatment of the acne itself, in combination with the appropriate mental health support, offers the highest chance of improving the quality of life of acne sufferers.

The Impact of Acne on Social Interactions

Acne Induced Depression by Age Group (Uhlenhake)
Acne Induced Depression by Age Group (Uhlenhake)

Acne vulgaris can have a very negative impact on the social interactions of an affected person. One on hand, acne causes psychological trauma to the sufferer, often decreasing their confidence and self-esteem. On the other hand, the outside world can be hurtful and harsh. Facing challenges from both sides, acne sufferers will often withdraw from interpersonal relationships. Some acne sufferers develop symptoms of anti-social behavior patterns. Anger levels tend to be elevated in acne sufferers.

For acne sufferers who do withdraw from interpersonal relationships and social interactions, the increasing isolation increases the danger of developing a self reinforcing cycle of self loathing. Basically, it’s tough to function normally when you are dealing with problem acne.

Acne and Suicide

Research indicates that people who have acne vulgaris have increased rates of both suicide ideation (thinking about suicide) and suicide itself. The fact that acne symptoms can cause and worsen symptoms of clinical depression make it a risk factor for suicide.

The Role of Acne Medications in Depression

There are some acne medications that are suspected to cause or worsen symptoms of depression. People with a history of depression, mood disorders or any other mental health issue, should discuss these with their medical provider.

Isotretinoin (Accutane) is the acne medication with the most high-profile association with depression and suicide. It has been alleged numerous times that Accutane can cause depression and suicidal thoughts. The association between Isotretinoin and depression primarily originated from parents whose children committed suicide, while taking Isotretinoin. However, the majority of the clinical research indicates that Isotretinoin treatment is not statistically related to suicide or suicide attempts.

Isotretinoin Roaccutane Packaging
Isotretinoin (Roaccutane, Accutane)

The alleged association between Isotretinoin (Accutane) and depression was brought to national attention in the United States when Congressman Bart Stupak claimed that Accutane was responsible for his son’s suicide. Congressman Stupak gave a congressional statement to that effect. Many other parents have made similar claims.

However, the alleged relationship between the treatment of acne with Isotretinoin and suicide is not strongly supported by the available scientific evidence. It is also possible that the severe acne symptoms themselves contributed to suicide and suicide attempts in many of these individuals. Researchers have shown that acne itself is an important contributor to depression. Thus, effective treatment of acne can improve symptoms of depression and reduce the frequency of suicide ideation.

This conflict between parents and researchers may come down to a difference in perception. Non-acne sufferers often underestimate how traumatizing acne is for someone with the disease. Acne patients who experience depression may become withdrawn, and hide their true feelings from the people around them. When an individual commits suicide, it can seem like it came out of nowhere. That person may have seemed OK on the surface, but they were battling deep emotional trauma on the inside. Family and friends of those left behind often look for a reason, an explanation for how the tragedy could have happened. It is easy to assign the blame to a pill, a real world menace, the product of a callous corporation. It helps to have a reason, something or someone to blame for your loss. It’s understandable. But being understandable does not necessarily make something true.

In conclusion, it is certainly possible that treatment of acne with Isotretinoin could cause psychological symptoms, including depression, but the causative relationship between Isotretinoin and suicide is not supported by the current body of scientific evidence.

References

Acne in Victorian adolescents: Associations with age, gender, puberty and psychiatric symptoms. Kilkenny, et al. 1997.
Acne prevalence, knowledge about acne and psychological morbidity in mid-adolescence: a community-based study. Smithard, et al. 2001.
Acne vulgaris and depression: a retrospective examination. Uhlenhake, et al. 2010.
Acne Vulgaris and the Quality of Life of Adult Dermatology Patients. Lasek, et al. 1998.
Acne, anxiety, depression and suicide in teenagers: A cross-sectional survey of New Zealand secondary school students. Purvis, et al. 2006.
Anxiety, Depression, and the Nature of Acne in Adolescents. Aktan, et al. 2000.
Anger and acne: implications for quality of life, patient satisfaction and clinical care. Rapp, et al. 2004.
Association of suicide attempts with acne and treatment with isotretinoin: retrospective Swedish cohort study. Sundstrom, et al. 2010.
Body dysmorphic disorder symptoms among patients with acne vulgaris. Bowe, et al. 2007.
Experiences of appearance-related teasing and bullying in skin diseases and their psychological sequelae: results of a qualitative study. Magin, et al. 2008.
Prevalence, Severity, and Severity Risk Factors of Acne in High School Pupils: A Community-Based Study. Ghodsi, et al. 2009.
Psychiatric Aspects of the Treatment of Mild to Moderate Facial Acne. Gupta, et al. 1990.
Psychological sequelae of acne vulgaris. Magin, et al. 2006.
Psychosocial Aspects of Acne Vulgaris: A Community-based Study with Korean Adolescents. Do ,et al. 2009.
Psychosocial effect of common skin diseases. Barankin, et al. 2002.
Quality of life issues for South Africans with acne vulgaris. Mosam, et al. 2005.
Self-esteem and body satisfaction among late adolescents with acne: Results from a population survey. Dalgard, et al. 2008.
Social Anxiety Level in Acne Vulgaris Patients and its Relationship to Clinical Variables. Yarpuz, et al. 2008.
Suicide in Dermatological Patients. Cotterill, et al. 1997.
The quality of life in acne: a comparison with general medical conditions using generic questionnaires. Mallon, et al. 1999.

What Causes Acne?

Inflammatory Acne Papules Skin and Cellular View
Healthy and Infected Follicle
Healthy and Infected Follicle

Acne is a complex disease and many factors can contribute to the development of acne symptoms. Every case of acne is unique and the blend of factors that cause acne varies between individuals. A detailed discussion about What Is Acne? can be found here. Below is a list of things that are major contributors to the development of acne:

Genetics

Genetic Information is Encoded in DNA
Genetic Information is Encoded in DNA

An individual’s genetic makeup is a dominant factor in determining the likelihood of developing acne and how severe their acne symptoms will be. People inherit their genes from their parents. If either of your parents experienced significant acne symptoms, you are substantially more likely to develop acne yourself.

Genetics impact the structure of the hair follicle, sebaceous gland activity, hormone levels and the immune response to bacteria. For example, many people who suffer from inflammatory acne have immune cells that are less effective at killing the acne bacteria or produce more inflammatory molecules than the general population.  As a result of genetic differences, their body responds more vigorously (but less effectively) to acne causing bacteria than the average person. This can result in more frequent and more severe acne breakouts.

Hormones

Androgens Drive Muscle Growth
Androgen Hormones Drive Muscle Growth and Acne

Hormones are an important factor in the development of acne. Hormones regulate many of the factors that are involved in acne, including the activity of the sebaceous glands, the production of sebum and the immune system’s response to acne-causing bacteria (eg. P. acnes). Hormones largely explain why women tend to experience worsening acne symptoms during certain times of their menstrual cycle, or during/after pregnancy. Hormones also explain why acne symptoms tend to peak during adolescence for males.

Pregnancy
Pregnancy can Trigger Acne Symptoms

Men and women tend to experience acne differently and much of this difference can be explained by hormones. Men are more likely to develop acne during puberty and are more likely to develop severe and inflammatory forms of the disease. Acne symptoms tend to peak during adolescence and recede during a male’s mid 20’s. In contrast, women tend to experience less acne and less severe acne than men, but rates of acne actually increase for women in the 20-40 age range. Many women who have never had complexion problems begin to experience acne symptoms during pregnancy, and sometimes acne continues to persist after completion of the pregnancy.

Men, particularly adolescent males, produce abundant quantities of male hormones called androgens. Androgens include hormones like testosterone. Among other things, androgens stimulate the growth of sebaceous glands, which increases the amount of sebum produced by the skin. Increased sebum production fosters the growth of bacteria that feed on sebum, such as P. acnes. Additionally, high levels of sebum production can increase the incidence of hyper-keratinized follicular plugs (clogged pores) that encourage the development of acne symptoms like pimples, nodules and cysts.

Bacteria

Propionibacterium acnes (Toyoda, et al)
Propionibacterium acnes (Toyoda, et al)

Acne, and inflammatory acne in particular, is usually connected to bacteria growing deep within pores and hair follicles in the skin. The bacteria most commonly associated with acne symptoms is Propionibacterium acnes (P. acnes). These bacteria produce molecules which cause an immune response, leading to inflammation and acne symptoms.

High levels of bacterial growth within follicles is associated with a higher incidence of acne and more severe symptoms.  Although P. acnes bacteria are generally thought of as a causative agent of acne, other bacteria (eg. Staphylococcus aureus) can also live in the skin and may also contribute to the development of acne. Antibiotics are commonly used to control the growth of bacteria and can greatly improve symptoms for many acne sufferers.

There are many different strains of P. acnes bacteria and many of these strains have developed resistance to one or many different antibiotics. As a result, some antibiotics, including erythromycin and tetracycline, are becoming less effective in some countries (eg. United States) because many people who suffer from acne carry strains of bacteria that are resistant. Fortunately, there are still many antibiotics available that do not have this shortcoming.

Environment

UV Light is an Environmental Condition
UV Light is an Environmental Condition

Environmental conditions, like temperature, sun exposure, humidity and allergens can play a big role in acne outbreaks. Low temperatures may decrease the fluidity of the sebum passing through the follicle and increase the risk of developing a plug. Or low humidity levels can dry the skin, causing the body to increase sebum production in a bid to protect the skin, which then increases the formation of clogged pores and the growth of acne-causing bacteria. Sunlight can affect both the bacteria and the skin, causing physiological changes or damage to various structures. Allergic reactions may exacerbate skin problems, or cause new ones.

Many people notice that their acne tends to improve or worsen depending on the weather, and this is because the environmental conditions can directly affect the way the body functions. The effect of specific environmental conditions on acne symptoms varies greatly between individuals.

Stress

Stressed Out
Stress

Stress is well known to disrupt normal hormonal balance and depress the immune system. Both of these changes can lead to a worsening of acne symptoms. Acne is a type of infectious disease, and elevated levels of stress can make people more susceptible to all types of infection, including acne.

Many people observe that they tend to break out especially bad after pulling an all-nighter, drug/alcohol consumption or other activities that put stress on the body. Inadequate sleep is a very common form of stress. Avoiding stress and identifying strategies to reduce stress (eg. Exercise, Yoga, Meditation, etc) are important components of a holistic approach to treating acne.

Diet

High Glycemic Foods can Increase Risk of Acne
High Glycemic Foods can Increase Risk of Acne

Scientific evidence does not appear to support the common claims that there is a connection between eating greasy foods or chocolate and the development of acne. However, scientific research has identified a connection between high glycemic index diets and increased incidence of acne. High glycemic diets are those that are high in sugar and simple carbohydrates.

Excessive consumption of sugar and starch is the primary cause of high blood sugar levels, and blood sugar levels are the primary regulator of metabolic function. Consistently elevated blood sugar levels are a type of stress, and they appear to negatively affect the body in ways that are similar to other forms of stress. This type of metabolic stress may cause or worsen acne symptoms in some individuals. Besides increased acne symptoms, high blood sugar levels can lead to other problems, like type 2 diabetes.

Eating a balanced, healthy diet that is rich in protein, whole grains and vegetables is important for overall health and can help minimize acne symptoms. There is some evidence that specific dietary plans (eg. Mediterranean or Vegan diets) may help improve acne for some individuals, but these claims require further scientific investigation.

References

Pathogenesis of Acne. Toyoda, et al. 2001.
Correlation Between Serum Levels of Insulin-like Growth Factor 1, Dehydroepiandrosterone Sulfate, and Dihydrotestosterone and Acne Lesion Counts in Adult Women. Cappel, et al. 2005.
Acne in Victorian adolescents: Associations with age, gender, puberty and psychiatric symptoms. Kilkenny, et al. 1997.
Post-adolescent acne: a review of clinical features. Goulden, et al. 1997.
Prevalence of facial acne in adults. Goulden, et al. 1999.
Neuroimmunology of Stress: Skin Takes Center Stage. Arck, et al. 2006.
Neuroendocrine regulation of sebocytes and a pathogenetic link between stress and acne. Zouboulis, et al. 2004.
Sebaceous glands in acne patients express high levels of neutral endopeptidase. Nakamura, et al. 2002.
The Response of Skin Disease to Stress. Chiu, et al. 2003.
Stress, Acne and Skin Surface Free Fatty Acids. Kraus. 1970.
Transient Receptor Potential Vanilloid-1 Signaling as a Regulator of Human Sebocyte Biology. Toth, et al. 2009.
Comparative Chemistry of Sebum. Nikkari. 1974.
Comprehensive analysis of the major lipid classes in sebum by rapid resolution high-performance liquid chromatography and electrospray mass spectrometry. Camera, et al. 2010.
Quantitative evaluation of sebum lipid components with nuclear magnetic resonance. Robosky, et al. 2008.
Sebaceous gland lipids. Picardo, et al. 2009.
Variation in Sebum Fatty Acid Composition Among Human Adults. Green, et al. 1984.
Sebaceous gland lipids: friend or foe? Smith, et al. 2007.
Sebum analysis of individuals with and without acne. Pappas, et al. 2009.
Does facial sebum excretion really affect the development of acne? Youn, et al. 2005.
Sebum output as a factor contributing to the size of facial pores. Roh, et al. 2006.
Comparison of sebum secretion, skin type, pH in humans with and without acne. Kim, et al. 2006.
Can sebum reduction predict acne outcome? Janiczek-Dolphin, et al. 2010.
Human Neutrophils Convert the Sebum-derived Polyunsaturated Fatty Acid Sebaleic Acid to a Potent Granulocyte Chemoattractant. Cossette, et al. 2008.
Peroxisome Proliferator-Activated Receptors Increase Human Sebum Production. Trivedi, et al. 2006.
Sebum Free Fatty Acids Enhance the Innate Immune Defense of Human Sebocytes by Upregulating b-Defensin-2 Expression. Nakatsuji, et al. 2010.
Control of Human Sebocyte Proliferation in Vitro by Testosterone and 5-DHT is Dependent on the Localization of the Sebaceous Glands. Akamatsu, et al. 1992.
Differentiation of the sebaceous gland. Niemann. 2009.
Correlation of facial sebum to serum insulin like growth factor-1 (IGF-1) in patients with acne. Vora, et al. 2008.
The Role of Specific Retinoid Receptors in Sebocyte Growth and Differentiation. Kim, et al. 2000.
The Effect of Marked Inhibition of Sebum Production with 13-Cis-Retinoic Acid on Skin Surface Lipid Composition. Strauss, et al. 1980.
Regional and seasonal variations in facial sebum secretions: a proposal for the definition of combination skin type. Youn, et al. 2005.
Study of Psychological Stress, Sebum Production and Acne Vulgaris in Adolescents. Yosipovitch, et al. 2007.

The Types of Acne Scars

Icepick Acne Scars on Cheek (Fabbrochini)

Acne scars come in many different shapes, sizes and even colors.

Each type of acne scar has its own unique characteristics and features. Because of these differences, the available treatments for acne scars are not one size fits all. It is important to carefully choose the treatment that best matches your needs in order to achieve optimal results. Acne scars can be classified into three main groups: Depressed (pitted scars), Raised (keloid scars) and Discoloration scars.

Depressed (Pitted) Acne Scars

Acne Scar Types Drawing
Types of Depressed Acne Scars

Depressed scars are the most common type of scarring that results from inflammatory acne.  In general, all the depression scars rest on top of a patch of fibrous, collagen rich scar tissue.  This fibrous tissue anchors the base (bottom) of the scar to the sub-cutaneous tissue, maintaining the depression and preventing the regrowth of healthy tissue.

Effective treatments for depressed acne scars usually involve disrupting or removing this scar tissue to allow its replacement with functional, healthy tissue.

There are three main types of depressed acne scars:

Rolling scars

Rolling Acne Scars on Cheeks
Rolling Acne Scars on Cheeks

Rolling acne scars are relatively broad depressions in the skin that have rounded, sloping edges. The combination of several of these types of scars in a region of skin gives it a rolling appearance, hence the name.

Rolling scars are common for in individuals who have had patches of skin that have been afflicted by long-term inflammatory acne. They tend to become more pronounced as the skin ages and loses its original elasticity and fullness.

Because rolling scars have sloping edges, many of the available scar treatment techniques are capable of producing positive results. Laser resurfacing (ablative and non-ablative), chemical peels, micro-dermabrasion, needling, subcision and even red light phototherapy can produce improvements in the appearance of rolling scars. Cosmetic fillers are also occasionally used, but many times the large size of the affected area makes fillers an unappealing option.

Boxcar scars

Boxcar Acne Scars on Temple (Fabbrochini)
Boxcar Acne Scars on Temple (Fabbrochini)

Boxcar acne scars are also relatively broad depressions, but they have steep, defined edges.

Because box car scars have steeper edges than rolling scars, it is more difficult to smooth them out and blend them into the surrounding skin. Laser resurfacing, particularly ablative laser resurfacing (eg. Er:YAG, Nd:YAG, CO2) often produces good results. However, many laser treatments may be necessary to achieve maximum improvement.

Box car scars often cover smaller areas than rolling scars and can be better candidates for cosmetic fillers. Shallow box car scars can be treated with chemical peels and/or micro-dermabrasion, but these treatments are not very effective for deep scars. Surgical options include punch- out excisions, needling and surgical subcisions.

Icepick scars

Ice Pick Acne Scars on Cheek
Icepick Acne Scars on Cheek

Icepick acne scars are deep and narrow scars. In many cases, icepick scars resemble a large, empty pore in the skin.

Ice pick scars are often the most difficult type of acne scar to treat without surgical procedures. Ice pick scars are often quite deep, making them very difficult to treat with standard resurfacing techniques. Chemical peels, micro-dermabrasion and many types of laser resurfacing are unlikely to have a significant impact on ice pick scars because those techniques do not remove enough tissue to be effective.

Some forms of laser therapy may be effective at disrupting the underlying scar tissue. Because ice pick scars are quite narrow, punch-out excisions are a popular, mildly invasive and effective treatment technique.

Hypertrophic and Keloid Scars

Severe Hypertrophic Acne Scars (Goodman)
Severe Hypertrophic Acne Scars (Goodman)

Hypertrophic (aka Keloid) scars occur when excess scar tissue forms at the site of the injury. Hypertrophic scar are regions of fibrous and firm scar tissue which is raised relative to the surrounding healthy tissue. These scars present a set of different challenges than depressed scars and are addressed with different treatments.

When scar tissue forms in great excess, it can become a large nodule of dense, rubbery scar tissue that is known as a keloid. The development of hypertrophic and keloid scars is less common in acne patients than the development of depressed scars. A number of factors can potentially be involved in the process, including acne severity and duration, genetics and secondary infections.

Because hypertrophic acne scars are raised, they are can often be effectively treated with ablative laser resurfacing and micro-dermabrasion. They can also be surgically removed. Hypertrophic scars are generally less responsive to treatments like chemical peels, because the scar tissue is much more resistant to the ingredients in a chemical peel than healthy tissue.

Discoloration and Pigmentation Scarring

The tissue damage caused by inflammatory acne can cause many abnormal conditions in the skin, besides the formation of fibrous scar tissue. Perhaps the most common long-term form of acne scarring is the abnormal discoloration of the skin.

Hyper-pigmentation

Hyper-pigmentation is a condition where elevated levels of the pigment melanin accumulate in the skin. This creates the appearance of freckle-like spots or blotches. Hyper-pigmentation occurs when melanocytes (the cells that produce the melanin pigment) begin to proliferate at the site of injury, or when an existing population of melanocytes begins to produce excess amounts of melanin. Both of these events can result from the trauma caused by an inflammatory acne lesion.

Hyper-pigmentation is often treated with light and laser treatments that specifically target melanin, such as KTP Lasers, Pulsed Dye Lasers (PDL), and Intense Pulsed Light (IPL) therapy. Hyperpigmentation is also addressed with the prescription medications like hydroquinolone, which inhibits the production of melanin, and topical Retinoids, which increase the rate of cellular turnover in the skin.

Hypo-Pigmentation

Hypopigmented Macular Acne Scarring (Goodman)
Hypopigmented Macular Acne Scarring (Goodman)

Hypo-pigmentation occurs when melanocytes are depleted from the injury site or lose their ability to produce melanin. This is often the case in areas of skin that have been replaced with scar tissue, which tends to have a light, pinkish appearance. It can also occur in otherwise healthy looking regions of skin.

Hypo-pigmentation is generally more noticeable in those individuals with darker base skin tones. Vitiligo is a condition in which melanocytes lose the ability to produce melanin. There are not many effective treatments available for hypo-pigmentation, although chemical peels and laser resurfacing may be helpful for some individuals.

Erythema (Permanent Redness)

Red Erythematous Acne Scars on Cheek
Red Erythematous Acne Scars on Cheek

Erythema is a condition in which small capillaries near the surface of the skin become damaged or permanently dilated. This condition presents as a region of redness in the skin. Occasionally, individual capillaries are visible. Erythema is somewhat common in acne patients and is most visible in patients with lighter skin tones.

Erythema may be treated with topical prescription medications to decrease vasodilation, but the results are usually temporary. Erythema generally responds well to laser and light based treatments that selectively target hemoglobin, such as Argon and Pulsed Dye Lasers. Red Light Phototherapy may also be a useful treatment for erythema in some individuals.

Acne Scar Images

References

Acne Scars: Pathogenesis, Classification and Treatment. Fabbrochini, et al. 2010.
Resurfacing of Different Types of Facial Acne Scar With Short-Pulsed, Variable-Pulsed, and Dual-Mode Er:YAG Laser. Woo, et al. 2004.
Resurfacing the Acne Scarred Face. Fulton, et al. 1999.
The Management of Post-Acne Scarring. What are the Options for Treatment? Goodman, et al. 2000.

What Does Non-Comedogenic Mean?

Acne Patients Should Avoid Comedogenic Substances

Answer: Comedogenicity refers to the potential of a substance to cause a comedo, a plugged or inflamed pore.

Non-comedogenic means that in testing, the substance or product has not been shown to cause comedos (clogged or inflamed hair follicle). Some substances (eg. coal tar) are highly comedogenic and produce a type of allergic, acne-like reaction. There is not a clear consensus when it comes to the comedogenicity of many substances, with different tests yielding different results.

How is comedogenicity determined?

Comedogenicity Testing is Commonly Performed on Rabbit Ears
Comedogenicity Testing is Commonly Performed on Rabbit Ears

The large majority of comedogenicity testing is done on animals, often using a rabbit ear model. In this test, the substance is applied to the inside of the rabbit’s ear, which has a similar structure as human facial skin. The development of comedos is quantified to evaluate the relative comedogenicity of a substance. In some cases, human volunteers are used to evaluate substances. In these tests, the most common treatment area is the skin on the back.

What kinds of things impact comedogenicity?

Rabbit Ear Comedogenicity Testing (Fulton)
Rabbit Ear Comedogenicity Testing (Fulton)

Comedogenicity is a complicated process that can vary from individual to individual. One interesting observation is that human sebum is itself comedogenic. A substance can be comedogenic for several reasons. It can contribute directly to the formation of a plug in the hair follicle. This could potentially occur with a substance that triggers the coagulation of free sebum.

A substance could also be comedogenic because it triggers an allergic reaction and/or inflammation. Substances like SLS (sodium lauryl sulfate) are common ingredients in topical preparations and but can cause allergic reactions in some individuals and are generally considered comedogenic.

Additionally, a substance can serve as a direct food source for the bacteria responsible for acne, Propionibacterium acnes. P. acnes bacteria eat fatty acids as one of their primary food sources and certain substances like olive oil or other vegetable oils could potentially serve as food sources for these bacteria and encourage their growth. Increased bacteria levels in the skin can then stimulate a local immune response, inflammation and comedogenecity.

Lastly, relatively harmless substances can be converted into allergens and comedogens by the enzymes present in the skin, or even by UV light.

Common Comedogenic Substances

There are several lists of comedogenic substances available in different places on the internet. However, a review of the scientific literature reveals a serious lack of actual testing on commonly used substances. This may be because many companies do their own testing and do not publish the results, but it also casts some doubt on some of these online comedogenic substances lists.

We are currently working to compile a comprehensive comedogenic substance lists from published scientific journal articles. Until then, we have included this table from the original comprehensive comedogenicity testing done by Dr. Fulton, et al.  Comedogenicity and irritancy are graded on a scale of 0 to 5, with 0 being no effect and 5 being highly comedogenic:

Comedogenicity Testing Results 3 (Fulton)
Comedogenicity Testing Results 3 (Fulton)
Comedogenicity Testing Results 2 (Fulton)
Comedogenicity Testing Results 2 (Fulton)
Comedogenicity Testing Results 1 (Fulton)
Comedogenicity Testing Results 1 (Fulton)

References

Comedogenicity and Irritancy of Commonly Used Ingredients in Skin Care Products. Fulton, et al. 1989.
A re-evaluation of the comedogenicity concept. Draelos, et al. 2006.
Comedogenicity of Squalene Monohydroperoxide in the Skin after Topical Application. Chiba, et al. 2000.
An Experimental Study on the Comedogenicity of Several External Contactants. Ahn, et al. 1985.

Does Greasy Food, Milk or Chocolate Cause Acne?

Pepperoni Pizza

Answer: Not exactly

At least not in the way you might think. Anecdotal associations between acne and particular foods like chocolate, ice cream and pizza have been discredited by scientific research. But research does point to a connection between overall diet and the development of acne symptoms.

Researchers have shown that people whose diets include lots of high glycemic index foods (foods that are high in sugar and simple carbohydrates) tend to experience acne at a greater frequency than those who have low glycemic index diets. However, there is no clear scientific consensus on why this connection exists. Some experts believe that high glycemic index diets may have negative impacts on hormone balance and the immune system.

There many widely held beliefs about the relationship between certain types of food and acne symptoms. Three of the common are:

Assumption #1: Eating Greasy Food Causes Greasy Skin

Pizza
Pizza

Mostly False. The grease that you eat is not the same grease that makes your skin oily. Genetics, hormones, stress and environmental factors are much more important players than consumption of fatty or greasy foods when it comes to oily skin

The substance that makes your skin feel and look greasy is not actually grease at all – it is a natural substance called sebum. The purpose of sebum is to moisturize and protect the skin. Sebum is produced by a specialized structures called sebaceous glands, which are located deep inside of hair follicles. Sebum is produced from the break-down of sebocytes, which are the specialized cells that make up the sebaceous gland. Sebocytes are rich in lipids (fatty acids) and triglycerides (fats and oils). The sebocytes nearest to the hair follicle die and then dissolve, releasing their contents into the hair follicle. The faster the sebaceous gland proliferates (grows), the faster this process of cell death and sebum production takes place, and the more oily the skin becomes. But eating more grease and fat does not necessarily cause this process to happen any faster.

It is also important to point out that oil is a generic term for a diverse class of molecules. The oils (lipids and triglycerides) in sebum are not the same as the oils that you consume when you eat things like fried foods. There are a lot of intermediate steps between the consumption of dietary oil and the synthesis of sebum, and this makes a direct connection between the two unlikely.

Assumption #2: Chocolate Causes Acne

Chocolate Truffles
Chocolate Truffles

Partially False. Chocolate itself has not been shown to have a direct connection with acne symptoms. There have been at least two studies that directly examined the relationship between chocolate and acne. In both of these studies, the researchers found no correlation between chocolate consumption and acne.

However, many chocolate-containing products are also high in sugar or high-fructose corn syrup, and are therefore high glycemic index foods. Research has shown that diets high in sugar and simple carbohydrates may contribute to acne symptoms.

Chocolate is generally a mixture of ingredients, and different kinds of chocolate can have a dramatically different composition of ingredients, such as sugar. It is also possible for people to develop allergic reactions to particular foods, including chocolate, and these reactions can produce acne-like symptoms. However, most cases an allergic reaction would also have additional symptoms including, itching, hives, throat swelling, fever, rash, joint pain, etc.

Assumption #3: Milk Causes Acne

Milk
Milk

Possibly True. There are a handful of studies that suggest a relationship between high levels of milk consumption and increased incidence of acne. The authors of these studies suggest that it is possible that hormones in the milk (or hormones stimulated by milk consumption) may be to blame. A particular hormone called Insulin Growth Factor 1 (IGF-1) is present in milk may cause changes in metabolism and hormone balance that can impact acne symptoms.

Whether or not milk consumption actually causes acne symptoms (and whether this is true for all people) remains to be scientifically proven. People have blamed a lot of medical conditions on milk consumption. There is a large group of people who swear that by stopping milk consumption they were relieved of a range of medical problems, from respiratory infections to acne vulgaris. Not all of these claims are true.

Milk consumption may also impact the balance of sex hormones, like androgens and estrogens (male and female sex hormones). Several studies have demonstrated that elevated androgen levels are associated with more severe acne symptoms in some patients. It is also possible that people with certain types of milk allergies could exhibit acne-like symptoms.

In conclusion, there is some evidence that milk may contribute to symptoms of acne vulgaris, but the exact relationship between milk and acne is not well understood. Regardless, for many people it’s worth a shot to cut milk out of their diet for a few weeks and see if that helps improve their acne symptoms.

Glycemic Index Reference for Common Foods

Glycemic Index Values for  Common Foods
Glycemic Index Values for Common Foods

References

Good Calories, Bad Calories: Fats, Carbs, and the Controversial Science of Diet and Health (Vintage). Taubes. 2008.
The Clear Skin Diet. Logan, et al. 2007.
Glycemic Index and Glycemic Load of Foods. DietGrail. 2011.
Eat, Drink, and Be Healthy: The Harvard Medical School Guide to Healthy Eating. Willett, et al. 2005.
A systematic review of the evidence for ‘myths and misconceptions’ in acne management: diet, face-washing and sunlight. Magin, et al. 2005.
Diet and acne: a review of the evidence. Spencer, et al. 2009.
A low-glycemic-load diet improves symptoms in acne vulgaris patients: a randomized controlled trial. Smith, et al. 2007.
Does diet really affect acne? Ferdowsian, et al. 2010.
Effect of Chocolate on Acne Vulgaris. Fulton, et al. 1969.
Milk consumption and acne in teenaged boys. Adebamowo, et al. 2008.
Role of insulin, insulin-like growth factor-1, hyperglycaemic food and milk consumption in the pathogenesis of acne vulgaris. Melnik, et al. 2009.