What is acne?

Acne is a disorder of the hair follicles and sebaceous glands. The glands become clogged, leading to pimples and cysts.

Acne is very common--people of all races and ages have acne. In fact, the majority of individuals in the U.S. between 11 and 30 years old will be affected by this condition. Even people in their forties and fifties can have acne. However, acne most often begins in puberty. During puberty, the male sex hormones (androgens) increase in both boys and girls, causing the sebaceous glands to become more active, resulting in increased production of oil (sebum).

How does acne develop?

The sebaceous glands produce sebum that normally travels via hair follicles to the skin surface. However, skin cells can plug the follicles, blocking the sebum coming from the sebaceous glands. When follicles become plugged, skin bacteria (called Propionibacterium acnes, or P. acnes) begin to grow inside the follicles, causing inflammation and pimples. According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, the most common types of pimples are:

Whiteheads. These pimples stay under the skin's surface.

Blackheads. These rise to the surface of the skin. Although these pimples are black, the color is not from dirt. It's from the process of oxidation when the sebum is exposed to air.

Papules. These are tender, small pink bumps.
Pustules. Pimples that have pus on the top and are red on the bottom of the lesion.
Nodules. These are hard, large, painful pimples that arise deep in the skin.
Cysts. Pus-filled, deep, painful pimples that often result in scars.
The basic acne lesion is called a comedo.
Acne can be superficial (pimples without abscesses) or deep (when the inflamed pimples push down into the skin, causing pus-filled cysts that rupture and result in larger abscesses).

What causes acne?

Rising hormone levels during puberty may cause acne. In addition, acne is often inherited. Other causes of acne may include the following:
Hormone level changes during the menstrual cycle in women
Hormone changes during pregnancy
Starting or stopping birth control pills
Certain drugs (such as corticosteroids, lithium, and barbiturates)
Oil and grease from the scalp, mineral or cooking oil, and certain cosmetics
Acne can be aggravated by squeezing the pimples or by scrubbing the skin too hard. Skin may also become irritated with friction or pressure from helmets, backpacks, or tight collars. Some environmental conditions such as pollution or humid conditions can also irritate the skin.
Where does acne occur?
Acne can occur anywhere on the body. However, acne most often appears in areas where there is a high concentration of sebaceous glands, including the following:
Upper back
The presentation of acne may resemble other skin conditions. Always consult your doctor for a diagnosis.
Treatment of acne
Specific treatment for acne will be determined by your doctor based on:
Your age, overall health, and medical history
Severity of the acne
Your tolerance for specific medications, procedures, or therapies
Expectations for the course of the condition
Your opinion or preference
The goal of acne treatment is to minimize scarring and improve appearance. Treatment for acne will include topical or systemic drug therapy. Depending on the severity of acne, topical medications (applied to the skin) or systemic medications (taken orally) may be prescribed by your doctor. In some cases, a combination of both topical and systemic medications may be recommended.
Topical medications to treat acne
Topical medications are often prescribed to treat acne. Topical medication can be in the form of a cream, gel, lotion, or solution. Examples include:
Benzoyl peroxide
Kills the bacteria (P. acnes)
Helps stop or slow down the growth of P. acnes and reduces inflammation
Stops the development of new acne lesions (comedones) and encourages cell turnover, unplugging pimples
Decreases comedo formation
Systemic medications to treat acne
Systemic medications, or oral antibiotics, are often prescribed to treat moderate to severe acne, and may include the following:
Treatment for severe, cystic, or inflammatory acne
Isotretinoin, an oral drug, may be prescribed for individuals with severe, cystic, or inflammatory acne that cannot be effectively treated by other methods to prevent extensive scarring. Isotretinoin reduces the size of the sebaceous glands that produce the skin oil, increases skin cell shedding, and affects the hair follicles, thereby reducing the development of acne lesions. Isotretinoin can clear acne in 85 percent of patients. However, the drug has major unwanted side effects, including psychiatric side effects. It is very important to discuss this medication with your doctor.
Isotretinoin must not be taken by women who are pregnant or who are able to become pregnant, because there is a very high likelihood of birth defects occurring in babies whose mothers take the medication during pregnancy. Isotretinoin can also cause miscarriage or premature birth. Because of these effects and to minimize fetal exposure, isotretinoin is approved for marketing only under a special restricted distribution program approved by the FDA. This program is called iPLEDGE.
The goal of the iPLEDGE program is to prevent pregnancies in females taking isotretinoin and to prevent pregnant females from taking isotretinoin. Requirements of the iPLEDGE program include:
Isotretinoin must only be prescribed by prescribers who are registered and activated with the iPLEDGE program.
Isotretinoin must only be dispensed by a pharmacy registered and activated with iPLEDGE.
Isotretinoin must only be dispensed to patients who are registered with and meet all the requirements of iPLEDGE
Female patients who can get pregnant are required to use birth control for one month prior to treatment, during treatment, and for one month after stopping treatment.
Pregnancy tests are required before, during, and after treatment.
Treatment for acne scars
Specific dermatological procedures to minimize acne scars will be determined by your doctor based on:
Your age, overall health, and medical history
Severity of the scar
Type of scar
Your tolerance for specific medications, procedures, or therapies
Your opinion or preference

Although acne often is a chronic condition, even if it lasts only during adolescence, acne can leave lifelong scars. Acne scars typically look like "ice pick" pit scars or crater-like scars. Although proper treatment for acne may help minimize scarring, several dermatological procedures may help to further minimize any acne scars, including the following:

Dermabrasion. Dermabrasion may be used to minimize small scars, minor skin surface irregularities, surgical scars, and acne scars. As the name implies, dermabrasion involves removing the top layers of skin with an electrical machine that "abrades" the skin. As the skin heals from the procedure, the surface appears smoother and fresher.

Chemical peels. Chemical peels are often used to minimize sun-damaged skin, irregular pigment, and superficial scars. The top layer of skin is removed with a chemical application to the skin. By removing the top layer, the skin regenerates, often improving the skin's appearance.

Derma filler injections. These are injected beneath the skin to replace the body's natural collagen that has been lost. Injectable dermal fillers are generally used to treat wrinkles, scars, and facial lines.

Laser resurfacing. Laser resurfacing uses high-energy light to burn away damaged skin. Laser resurfacing may be used to minimize wrinkles and fine scars.

Phototherapy or blue light therapy. Phototherapy using a blue light source has been shown to decrease the number of acne-causing bacteria with minimal side effects, such as dry skin. Blue light therapy does not use ultraviolet (UV) light, so it does not damage the skin as earlier types of light therapy did.

Pulsed light and heat energy (LHE) therapy. This type of combined light and heat therapy is believed to work by destroying acne-causing bacteria and by shrinking the oil-producing glands in the skin. The FDA has approved an LHE system that uses green light and heat pulses for treating mild to moderate acne.

Punch grafts. Punch grafts are small skin grafts used to replace scarred skin. A hole is punched in the skin to remove the scar, which is then replaced with unscarred skin (often from the back of the earlobe). Punch grafts can help treat deep acne scars.

Autologous fat transfer. An autologous fat transfer uses fat taken from another site on your own body and it is injected into your skin. The fat is placed beneath the surface of the skin to elevate depressed scars. This method is used to correct deep contour defects caused by scarring from nodulocystic acne. Because the fat may be reabsorbed into the skin over a period of months, there may be a need for the procedure to be repeated.

Treatment Programs

Massachusetts General Hospital understands that a variety of factors influence patients' health care decisions. That's just one reason why we're dedicated to ensuring patients understand their diagnosis and treatment options. Because a single option might not serve all patients, we offer a wide range of coordinated treatments and related services across the hospital. Patients should consult with their primary care doctor or other qualified health care provider for medical advice and diagnosis information.

Select a treatment program for more information:

Department of Dermatology

Dermatology Laser and Cosmetic Center The Massachusetts General Hospital Dermatology Laser & Cosmetic Center in Boston offers laser skin resurfacing, laser hair and tattoo removal, skin tightening, dermal fillers, and body contouring. Our center has more than 20 different lasers on-site allowing us to offer personalized services for virtually any skin condition. The Medical Dermatology Program The Medical Dermatology program at Massachusetts General Hospital is a full-service dermatology practice that provides care for all skin, hair and nail conditions.

Obstetrics and Gynecology

Midlife Women's Health Center The Massachusetts General Hospital Midlife Women’s Health Center brings together experts from more than 15 specialties to improve, promote and advance health care for women at menopause and beyond through research, collaboration and education. Plastic and Reconstructive Surgery

Laser Surgery Program

The Massachusetts General Hospital Laser Surgery Program offers a variety of noninvasive laser treatments for facial rejuvenation that can improve the appearance of fine lines, wrinkles, scars, sun damage, puffy eyes, and broken blood vessels, and treat skin conditions such as acne and rosacea.