Acne

Acne is a disorder resulting from the action of hormones and other substances on the skin's oil glands (sebaceous glands) and hair follicles. These factors lead to plugged pores and outbreaks of lesions commonly called pimples or "zits." Acne lesions usually occur on the face, neck, back, chest, and shoulders. Although acne is usually not a serious health threat, it can be a source of significant emotional distress. Severe acne can lead to permanent scarring.

Signs and Symptoms

Acne is commonly classified into mild, moderate, and severe.People with acne frequently have a variety of lesions. The basic acne lesion, called the comedo, or comedone, is simply an enlarged and plugged hair follicle. If the plugged follicle, or comedone, stays beneath the skin, it is called a closed comedone and produces a white bump called a whitehead. A comedone that reaches the surface of the skin and opens up is called an open comedone, or blackhead, because it looks black on the skin's surface. This black discoloration is due to changes in sebum as it is exposed to air. Other lesions include:

• Papules, inflamed lesions that usually appear as small, pink bumps on the skin and can be tender to the touch
• Pustules (pimples),papules topped by white or yellow pus-filled lesions that may be red at the base
• Nodules, large, painful, solid lesions that are lodged deep within the skin
• Cysts, deep, painful, pus-filled lesions that can cause scarring

Blackheads. Source: Wikimedia Commons, GNU FDL. Photo by David Shankbone.

Causes

Doctors describe acne as a disease of the pilosebaceous units (PSUs).

Found over most of the body, PSUs consist of a sebaceous gland connected to a canal, called a follicle, that contains a fine hair. These units are most numerous on the face, upper back, and chest. The sebaceous glands make an oily substance called sebum that normally empties onto the skin surface through the opening of the follicle, commonly called a pore. Cells called keratinocytes line the follicle.The hair, sebum, and keratinocytes that fill the narrow follicle may produce a plug, which is an early sign of acne. The plug prevents sebum from reaching the surface of the skin through a pore. The mixture of oil and cells allows a type of bacteria called Propionibacterium acnes (P. acnes) that normally lives on the skin to grow in the plugged follicles. These bacteria produce chemicals and enzymes and attract white blood cells that cause inflammation. (Inflammation is a reaction of living tissue to disease or injury and is marked by four signs: swelling, redness, heat, and pain.) When the wall of the plugged follicle breaks down, it spills everything into the nearby skin—sebum, shed skin cells, and bacteria—leading to acne lesions, or pimples.

The exact cause of acne is unknown, but doctors believe it results from several related factors. One important factor is an increase in hormones called androgens (male sex hormones). These increase in both boys and girls during puberty and cause the sebaceous glands to enlarge and make more sebum. Hormonal changes related to pregnancy or to starting or stopping birth control pills can also cause acne.

Another factor is heredity or genetics. Researchers believe that the tendency to develop acne can be inherited from parents. For example, studies have shown that many school-age boys with acne have a family history of the disorder. Certain drugs, including androgens and lithium, are known to cause acne. Some cosmetics may alter the cells of the follicles and make them stick together, producing a plug.

Provocative factors

Factors that can cause an acne flare include:

• Changing hormone levels in adolescent girls and adult women 2 to 7 days before their menstrual period starts
• Oil from skin products (moisturizers or cosmetics) or grease encountered in the work environment (for example, a kitchen with fry vats)
• Pressure from sports helmets or equipment, backpacks, tight collars, or tight sports uniforms
• Environmental irritants, such as pollution and high humidity
• Squeezing or picking at blemishes
• Hard scrubbing of the skin
• Stress

Myths

There are many myths about what causes acne.^[1] Chocolate and greasy foods are often blamed, but there is little evidence that foods have much effect on the development and course of acne in most people. Another common myth is that dirty skin causes acne; however, blackheads and other acne lesions are not caused by dirt. Stress doesn't cause acne, but research suggests that for people who already have acne, stress can make it worse.

Diagnosis

Acne can usually be diagnosed by the presence of the characteristic lesions. Several other conditions should be considered as well.^[2]

Acne rosacea

Also known as simply rosacea, this skin disease resembles acne but occurs in older adults, and, unlike acne vulgaris, tends to affect the head only and to worsen in sunlight. The skin of the nose may enlarge and redden, and the eyelids may be inflamed (blepharitis). It is treated differently from acne vulgaris and needs to be distinguished from it.

Steroid-induced acne

Steroid-induced acne can occur in bodybuilders or in others taking steroids.

Acne neonatorum and acne infantum

Acne neonatorum and acne infantum are outbreaks of lesions in babies, often on the face. Usually these clear up in a few weeks.

Folliculitis

Folliculitis is inflammation of the hair follicles which, unlike acne, does not include comedones.

Drug eruptions

Some patients have a reaction to a medication that can lead to a acne-like skin outbreak.

Acne fulminans

Acne fulminans is a serious condition that involves severe acne lesions with fever, abnormal white blood cell count, and arthritis.

Treatment

Acne is often treated by dermatologists (doctors who specialize in skin problems). These doctors treat all kinds of acne, particularly severe cases. Doctors who are general or family practitioners, pediatricians, or internists may treat patients with milder cases of acne.^[3]

The goals of treatment are to heal existing lesions, stop new lesions from forming, prevent scarring, and minimize the psychological stress and embarrassment caused by this disease. Drug treatment is aimed at reducing several problems that play a part in causing acne:

• abnormal clumping of cells in the follicles
• increased oil production
• bacteria
• inflammation.

All medicines can have side effects. Some medicines and side effects are mentioned in this booklet. Some side effects may be more severe than others.

Depending on the extent of the problem, the doctor may recommend one of several over-the-counter (OTC) medicines and/or prescription medicines. Some of these medicines may be topical (applied to the skin), and others may be oral (taken by mouth). The doctor may suggest using more than one topical medicine or combining oral and topical medicines. Treatment should be individualized for each patient, as no one treatment works for everyone.^[3]

Treatment for blackheads, whiteheads, and mild inflammatory acne

Doctors usually recommend an OTC or prescription topical medicine for people with mild signs of acne. Topical medicine is applied directly to the acne lesions or to the entire area of affected skin.

There are several OTC topical medicines used for mild acne. Each works a little differently. Following are the most common ones:

• Benzoyl peroxide: destroys P. acnes, and may also reduce oil production
• Resorcinol: helps break down blackheads and whiteheads
• Salicylic acid: helps break down blackheads and whiteheads. Also helps cut down the shedding of cells lining the hair follicles
• Sulfur: helps break down blackheads and whiteheads.

Topical OTC medicines are available in many forms, such as gels, lotions, creams, soaps, or pads. In some people, OTC acne medicines may cause side effects such as skin irritation, burning, or redness, which often get better or go away with continued use of the medicine.

OTC topical medicines are somewhat effective in treating acne when used regularly; however, it may take up to eight weeks before there is noticeable improvement.

Treatment for moderate to severe inflammatory acne

Moderate to severe inflammatory acne may be treated with prescription topical or oral medicines, alone or in combination.

Topical medicines

Several types of prescription topical medicines are used to treat acne. They include:

• Antibiotics: help stop or slow the growth of bacteria and reduce inflammation
• Vitamin A derivatives ( Retinoid|retinoids): unplug existing comedones (plural of comedo), allowing other topical medicines, such as antibiotics, to enter the follicles. Some may also help decrease the formation of comedones. These drugs contain an altered form of vitamin A. Some examples are tretinoin (Retin-A), adapalene (Differin), and tazarotene (Tazorac).
• Others: may destroy P. acnes and reduce oil production or help stop or slow the growth of bacteria and reduce inflammation. Some examples are prescription-strength benzoyl peroxide, sodium sulfacetamide/sulfur-containing products, or azelaic acid (Azelex).

Like OTC topical medicines, prescription topical medicines come as creams, lotions, solutions, gels, or pads. The doctor considers the patient's skin type when prescribing a product. Creams and lotions provide moisture and tend to be good choices for people with sensitive skin. People with very oily skin or who live in a hot, humid climate may prefer an alcohol-based gel or solution, which tends to dry the skin.

For some people, prescription topical medicines cause minor side effects, including stinging, burning, redness, peeling, scaling, or discoloration of the skin. With some medicines, such as tretinoin, these side effects usually decrease or go away after the medicine is used for a period of time.

As with OTC medicines, the benefits of prescription topical medicines are not immediate. Skin may seem worse before it gets better. It may take from four to eight weeks to notice improvement.

Prescription oral medicines

For patients with moderate to severe acne, doctors often prescribe oral antibiotics. Oral antibiotics are thought to help control acne by curbing the growth of bacteria and reducing inflammation. Prescription oral and topical medicines may be combined. Common antibiotics used to treat acne are tetracycline (Achromycin V), minocycline (Dynacin, Minocin), and doxycycline (Adoxa, Doryx, and Monodox).

Other oral medicines less commonly used are clindamycin (Cleocin), erythromycin, or sulfonamides (Bactrim). Some people taking these antibiotics have side effects, such as an upset stomach, dizziness or lightheadedness, changes in skin color, and increased tendency to sunburn. Tetracyclines may affect tooth and bone formation in fetuses and young children, and are not given to pregnant women or children under age 14. There is some concern, although it has not been proven, that tetracycline and minocycline may decrease the effectiveness of birth control pills. Therefore, a backup or another form of birth control may be needed. Prolonged treatment with oral antibiotics may be necessary to achieve the desired results.

Treatment for severe nodular or cystic acne

People with nodules or cysts should be treated by a dermatologist. For patients with severe inflammatory acne that does not improve with medicines such as those described above, a doctor may prescribe isotretinoin (Accutane), a retinoid (vitamin A derivative). Isotretinoin is an oral drug that is usually taken once or twice a day with food for 15 to 20 weeks. It markedly reduces the size of the oil glands so that much less oil is produced. As a result, the growth of bacteria is decreased.

Advantages of isotretinoin

Isotretinoin is a the most effective treatment for severe acne.^[4] After 15 to 20 weeks of treatment with isotretinoin, acne completely or almost completely goes away in most patients. In those patients where acne recurs after a course of isotretinoin, the doctor may institute another course of the same treatment or prescribe other medicines.

Disadvantages of isotretinoin

Isotretinoin can cause birth defects in the developing fetus of a pregnant woman. Women of childbearing age must not be pregnant or become pregnant while taking this medicine. Women must use two separate effective forms of birth control at the same time for one month before treatment begins, during the entire course of treatment, and for one full month after stopping the drug. They should talk with a doctor about when it is safe to get pregnant after taking isotretinoin.

Some people with acne become depressed by the changes in the appearance of their skin. Changes in mood may be intensified during treatment or soon after completing a course of medicines like isotretinoin. There have been a number of reported suicides and suicide attempts in people taking isotretinoin; however, the connection between isotretinoin and suicide or depression is not known.^[5] Nevertheless, feelings of intense sadness or symptoms of depression, such as loss of appetite, loss of interest in once-loved activities, or trouble concentrating, mean that it's time to see a doctor.

Other possible side effects of isotretinoin include:

• dry eyes, mouth, lips, nose, or skin (very common)
• itching
• nosebleeds
• muscle aches
• sensitivity to the sun
• poor night vision
• changes in the blood, such as an increase in fats in the blood (triglycerides and cholesterol)
• change in liver function.

To be able to determine if isotretinoin should be stopped if side effects occur, the doctor may test a patient's blood before starting treatment and periodically during treatment. Side effects usually go away after the medicine is stopped.

Treatments for hormonally-influenced acne in women

In some women, acne is caused by an excess of androgen (male) hormones. Clues that this may be the case include hirsutism (excessive growth of hair on the face or body), premenstrual acne flares, irregular menstrual cycles, and elevated blood levels of certain androgens.

The doctor may prescribe one of several drugs to treat women with this type of acne:

• Birth control pills: to help suppress the androgen produced by the ovaries
• Low-dose corticosteroid drugs, such as prednisone (Deltasone) or dexamethasone (Decadron, Hexadrol): to help suppress the androgen produced by the adrenal glands
• Antiandrogen drugs such as spironolactone (Aldactone): to reduce the excessive oil production.

Side effects of antiandrogen drugs may include irregular menstruation, tender breasts, headaches, and fatigue.

Procedural treatments for acne

Doctors may use other types of procedures in addition to drug therapy to treat patients with acne. For example, the doctor may remove the patient's comedones during office visits. Sometimes the doctor will inject corticosteroids directly into lesions to help reduce the size and pain of inflamed cysts and nodules.

Early treatment is the best way to prevent acne scars. Once scarring has occurred, the doctor may suggest a medical or surgical procedure to help reduce the scars.^[6] A superficial laser may be used to treat irregular scars. Dermabrasion (or microdermabrasion), which is a form of "sanding down" scars, is sometimes used. Another treatment option for deep scars caused by cystic acne is the transfer of fat from another part of the body to the scar. A doctor may also inject a synthetic filling material under the scar to improve its appearance.

Skin Care for People with Acne

Clean skin gently

People with acne should gently wash their face with a mild cleanser, once in the morning and once in the evening, as well as after heavy exercise. They should wash from under the jaw to the hairline and be sure to thoroughly rinse the skin. A doctor may recommend the best type of cleanser to use.

Using strong soaps or rough scrub pads is not helpful and can actually make the problem worse. Astringents are not recommended unless the skin is very oily, and then they should be used only on oily spots.

It is also important to shampoo the hair regularly. People with oily hair may want to wash it every day.

Avoid touching the skin

People with acne should avoid rubbing and touching skin lesions. Squeezing, pinching or picking blemishes can lead to the development of scars or dark blotches.

Shave carefully

Men who shave and who have acne should test both electric and safety razors to see which is more comfortable. When using a safety razor, they need to make sure the blade is sharp and should thoroughly soften the beard with soap and water before applying shaving cream. Shave should be done gently and only when necessary to reduce the risk of nicking the lesions.

Avoid sunburn or suntan

Many of the medicines used to treat acne can make the skin more prone to sunburn. A sunburn that reddens the skin or suntan that darkens the skin may make blemishes less visible and make the skin feel drier. However, these benefits are only temporary, and there are known risks of excessive sun exposure, such as more rapid skin aging and a risk of developing skin cancer.

Choose cosmetics carefully

While undergoing acne treatment, patients may need to change some of the cosmetics they use. All cosmetics, such as foundation, blush, eye shadow, moisturizers, and hair-care products should be oil-free. Choose products labeled noncomedogenic (meaning they don't promote the formation of closed pores). In some people, however, even these products may make acne worse.

For the first few weeks of treatment, applying foundation evenly may be difficult because the skin may be red or scaly, particularly with the use of topical tretinoin or benzoyl peroxide.

Related Problems

Acne is not a life-threatening disease in itself, but it can cause considerable psychological distress.^[7] Acne lesions are considered unattractive, and when they heal, they can scar. The scars may be small or very prominent, such as keloids.

There are treatments available for scars, and support groups to help people with psychologically distressing acne or scarring.

Chances of Developing Acne

People of all races and ages get acne. It is most common in adolescents and young adults. For most people, acne tends to go away by the time they reach their thirties; however, some people in their forties and fifties continue to have it. Persistent adult acne is particularly common in women.^[8][9]

Clinical Trials

For an extensive list of completed, ongoing, and upcoming clinical trials related to acne, go to Acne Clinical Trials.

Research

Medical researchers are working on new drugs to treat acne, particularly topical antibiotics to replace some of those in current use. As with many other types of bacterial infections, doctors are finding that, over time, the bacteria that are associated with acne are becoming resistant to treatment with certain antibiotics, though it is not clear how significant a problem this resistance represents.

Scientists are also trying to better understand the mechanisms involved in acne so that they can develop new treatments that work on those mechanisms. For example, one group of researchers is studying the mechanisms that regulate sebum production in order to identify ways to effectively reduce its production without the side effects of current medicines. Another group is trying to understand how P. acnes activates the immune system in order to identify possible immunologic interventions. Other areas of research involve examining the effects of isotretinoin on an area of the brain that might lead to depression and developing a laser system to treat acne and acne-related scars without damaging the outer layers of the skin.

Researchers in Germany have studied P. acnes and identified its genetic information (genome). This information may help researchers develop new treatments to target the bacteria.

References

1. ↑ Magin P, Pond D, Smith W, Watson A. A systematic review of the evidence for 'myths and misconceptions' in acne management: diet, face-washing and sunlight. Fam Pract. 2005 Feb;22(1):62-70. Epub 2005 Jan 11. Abstract | Full Text
2. ↑ Purdy S, de Berker D. Acne. BMJ. 2006 Nov 4;333(7575):949-53. Abstract | Full Text
3. ↑ ^{3.0 3.1} Haider A, Shaw JC. Treatment of acne vulgaris. JAMA. 2004 Aug 11;292(6):726-35. Abstract | Full Text
4. ↑ Akman A, Durusoy C, Senturk M, Koc CK, Soyturk D, Alpsoy E. Treatment of acne with intermittent and conventional isotretinoin: a randomized, controlled multicenter study. Arch Dermatol Res. 2007 Dec;299(10):467-73. Epub 2007 Aug 21. Abstract | Full Text
5. ↑ Marqueling AL, Zane LT. Depression and suicidal behavior in acne patients treated with isotretinoin: a systematic review. Semin Cutan Med Surg. 2007 Dec;26(4):210-20. Abstract | Full Text
6. ↑ Alam M, Dover JS. Treatment of acne scarring. Skin Therapy Lett. 2006 Dec-2007 Jan;11(10):7-9. Abstract | Full Text
7. ↑ Chuh A, Wong W, Zawar V. The skin and the mind. Aust Fam Physician. 2006 Sep;35(9):723-5. Abstract | Full Text
8. ↑ Goulden V, Stables GI, Cunliffe WJ. Prevalence of facial acne in adults. J Am Acad Dermatol. 1999 Oct;41(4):577-80. Abstract
9. ↑ Cunliffe WJ, Gould DJ. Prevalence of facial acne vulgaris in late adolescence and in adults. Br Med J. 1979 Apr 28;1(6171):1109-10. Abstract | Full Text

Links to Clinical Images

DermNetNZ: Acne Images

DermAtlas: Acne Images

Skinsight: Acne Images

SkinAtlas: Acne Images

External Links

American Academy of Dermatology: Acne

AcneNet

Acne.org Acne.org: Peer support