Reviewed on 2/16/2022

Facts on Acne

Papules, pustules (zits
Acne is not caused by eating "fast" foods, chocolate, or high-fat foods.

Acne is an inflammatory rash that is almost universal among individuals going through puberty in industrialized societies. It can, however, occur at all ages. Typical acne affects the skin of the face, chest, and back and rarely the neck and upper arms of teenagers and young adults.

Because acne typically occurs during a time of dramatic physical and psychological changes associated with the development of one's body image, it can exacerbate social withdrawal and even depression. Left untreated, severe acne can lead to disfiguring scarring which can be difficult to treat.

  • Several myths exist about acne. Here are the facts.
    • Acne is not a result of poor hygiene or infrequent washing. In other words, acne does not result from too much dirt on the skin or in the pores. Too much scrubbing may actually make acne worse.
    • Acne is not caused by eating "fast" foods, chocolate, or high-fat foods.
    • Acne is not a bacterial infection.

What Symptoms and Causes of Acne?

Several factors contribute to the development of acne. The primary problem is a change in the development of cells inside the hair follicle, leading to the formation of a plug or (comedo). The plug disrupts the normal movement of hair, skin cells, and grease (sebum), resulting in enlargement and eventually rupture of the hair follicle. A ruptured hair follicle spills its contents of oil and debris into the skin where it leads to swelling and causes redness (inflammation).

  • Propionibacterium acnes, a type of bacteria that normally lives in the skin hair follicles, also plays a role in acne. These bacteria produce substances that cause redness and irritation (inflammation). They also make enzymes, which dissolve the sebum from the oil glands in the skin into irritating substances. These substances also make the inflammation worse.
  • Certain hormones called androgens are an additional factor in causing acne. Androgens are male hormones that are present in both men and women but are present at higher levels in men. Androgens do two things: First, they enlarge the sebaceous glands in the skin. Second, they cause these glands to increase sebum (oil) production. The increased sebum production exacerbates plug formation and serves as more "food" for the bacteria. Androgens surge at puberty, which is why teens develop armpit and pubic hair and why boys develop facial hair and deeper voices. This hormonal surge also contributes to the development of acne in teens.
  • Estrogens, which are the female hormones, actually can help to improve acne in girls. A woman's monthly menstrual cycle is due to changes in the estrogen levels in her body. This is why acne in a female may get better and then get worse as she goes through her monthly cycle. A doctor may recommend acne treatment with birth control pills, which contain helpful estrogens.
  • Because severe acne can run in some families, there seems to be a significant hereditary predisposition to serious disease.
  • Anatomy of the hair follicle: Hair follicles exist on virtually all skin except for the palms of the hands and soles of the feet. Inside the follicle, the hair extends up from the deep layers of the skin and comes out of a pore. Near the surface, the oil gland (sebaceous gland) enters the hair follicle where it empties sebum at a relatively constant rate. The sebum lubricates the skin and provides a protective barrier to prevent drying. The skin on the face, chest, and back has an especially large number of sebaceous glands. These are the areas where acne occurs.
  • Acne lesions: There are two major types of acne lesions: noninflammatory and inflammatory. Noninflammatory acne lesions include blackheads (open comedones) and whiteheads (closed comedones). Open and closed comedones along with papules and pustules are referred to as papulopustular acne, a form of inflammatory acne. Nodular acne is the most severe form of inflammatory acne.
    • Noninflammatory acne: Open comedones result from the enlargement and dilation of a plug that forms from oil and skin cells inside the hair follicle.
      • The hair follicle pore remains open, exposing a black plug (known as a blackhead). The dark color is not dirt inside the pore. Instead, it is the oil inside the pore, which has become exposed to the outside air.
      • A closed comedo forms if the hair follicle pore remains closed. The plugin a closed comedo or whitehead is therefore not exposed to the outside air, and no black color develops. The closed comedo simply appears as a tiny, sometimes flesh-colored or white bump in the skin.
    • Inflammatory acne: Inflammatory acne lesions consist of red blemishes, pimples also called zits (papules, pustules), and larger, deeper swollen tender lesions (nodules).
      • Papules are closed comedones, which have become red, swollen, and inflamed.
      • Pustules are closed comedones, which become inflamed and begin to rupture into the skin, forming pustular heads of various sizes.
      • Nodules represent large, tender, swollen acne lesions, which have become intensely inflamed and ruptured under the skin. If untreated, these can produce scarring.

When Should I Call the Doctor About Acne?

  • Acne that does not improve with over-the-counter medicines should be evaluated by a doctor.
  • People with acne that is severe and tender or who already have scarring should also be seen by a doctor.
  • Women with acne who develop facial hair or have irregular periods require evaluation by a doctor.
  • Anyone with a sudden severe worsening of their acne or acne with fever and severe swelling should see a doctor immediately. These could be signs of a serious skin infection.

How Is Acne Diagnosed?

No specific tests are usually required for diagnosing or treating acne. A doctor will occasionally want to check hormone blood tests before starting some medications.

Are there Home Remedies for Acne?

  • Wash once or twice daily with soap and water to remove excess oil from the skin. Avoid scrubbing or using abrasives because this can irritate the skin and cause acne to worsen.
  • Over-the-counter acne medications can be used either at bedtime or during the day. Always follow the directions on any acne product. These products generally do not have any beneficial effects on inflammatory lesions, pimples, and are essentially used to prevent the development of new lesions. Therefore they should be applied to all of the skin in affected areas.
  • Many cover-up products are available without a prescription to improve the appearance of blemishes while they have a chance to heal. Most work well and should not worsen acne. If makeup is worn, it should be water-based, and the ingredients of the makeup should list water as a major component.
  • Some cosmetics and other skin-care products, however, can cause acne to worsen. Look for makeup, cosmetics, and skin-care products that claim to be non-comedogenic. This means that it does not cause or worsen acne.
  • It is of major importance that patient with acne does not manipulate their lesions. Manipulation (pinching, squeezing, etc.) of any type may result in the worsening of any existing disease, potentially enhancing the chance for scarring and producing more long-lasting pimples. It is prudent therefore to avoid magnifying mirrors.

What Is the Treatment for Acne?

The purpose of medical care is to prevent scarring until the disease characteristically spontaneously remits. Many treatment options are available to treat all forms of acne. Medications are the main treatment for acne and usually work well. Several preparations are available over the counter, while others require a prescription from a doctor.

  • Over-the-counter medications: Nonprescription or over-the-counter medications for acne are plentiful and can be effective for milder forms of acne. They come in the form of soaps, washes, and cleansers.
    • Many contain benzoyl peroxide, which does two things. First, benzoyl peroxide kills acne-promoting bacteria, which are thought to play a role in acne. Second, benzoyl peroxide can cause drying and flake off of the skin, which can help prevent the pores from becoming plugged. Plugged pores can develop into acne blemishes.
    • Salicylic-acid preparations can be of help in mild acne by loosening the superficial skin covering the follicular opening and promoting evacuation of the sebaceous plug.
    • Scrubbing excessively with any over-the-counter preparation can actually cause acne to worsen by additionally irritating the hair follicles.
  • Prescription medications: Doctors can prescribe medications when acne becomes moderate to severe or is not controlled by over-the-counter medications. Prescription drugs can be used effectively alone or in combination with other prescription and nonprescription medications.
    • Antibiotics: Antibiotics can be effective in treating most inflammatory acne (papules and pustules). They work by decreasing inflammation caused by bacteria and other irritating chemicals present in the sebaceous follicle.
      • Antibiotics may be applied to the skin in the form of gels and lotions or by way of pills. Giving an antibiotic by mouth is often needed for acne that is more severe.
      • Antibiotics may be combined with benzoyl peroxide, which is contained in over-the-counter medications, to form a topical solution that can be obtained with a doctor's prescription.
      • Antibiotics taken by mouth for relatively extended periods can be very effective in controlling acne. Although the development of resistant bacteria is a theoretical concern as a result of protracted courses of antibiotics, this does not seem to occur commonly in acne patients. Still, the goal of treatment regimens is to graduate patients of systemic antibiotics as soon as feasible. As with any systemic medication, they can be associated with more side effects than if applied to the skin and may interact with other drugs. Sensitivity to the sun can result in a "bad sunburn" in some people who take antibiotics in the tetracycline family.
    • Retinoids: Medicines structurally similar to vitamin A are useful in preventing several types of acne lesions. Topical retinoids are effective in treating the noninflammatory types of acne (blackheads and whiteheads).
      • Topical retinoids (applied directly to the skin) help to open clogged pores and produce a mild peeling effect. Drying and redness of the skin can be a frequent side effects and limit its usefulness in some patients.
      • An oral retinoid (isotretinoin) may be prescribed for treating the more extensive nodular and scarring type of acne or severe inflammatory acne, which has not responded to other treatments and is likely to cause scarring. All patients on isotretinoin will experience peeling and drying of the skin. Most patients who take the appropriate dosage for an appropriate duration should expect an extended remission in their acne. Isotretinoin is associated with a number of serious side effects, including birth defects in babies of women who become pregnant while taking the medicine. The drug can also cause elevated blood lipids. Your doctor must perform certain blood tests to check for these problems and to make sure you are not pregnant (assuming that it is possible) if you are given oral retinoids. Although there is no compelling evidence, depression and inflammatory bowel disease have been reported while taking oral retinoids. All patients on isotretinoin in the United States must be registered in a government-mandated program, the I PLEDGE PROGRAM, which is accessible online or by telephone. Besides the patient, the patient's physician and the dispensing pharmacy must also register with this program.
    • Other medications: A doctor may recommend other types of drugs or therapy to improve acne. For women, medications such as birth control pills or certain "water pills" (spironolactone) may be helpful. These drugs counteract the acne-causing effect of male hormones. Newer treatments for acne include the use of light or zinc. Your doctor can advise you whether these types of acne therapy might be good for you.

Acne Quiz IQ

What Is the Prognosis for Acne?

The prognosis for most cases of acne is excellent. Most people experience their worst acne during their teen years and grow out of it. The goal in all acne treatments is to prevent scarring. Severe acne left untreated for a long time can result in scarring. The scars can appear as pits (usually on the face) or as big, bumpy scars (usually on the chest and back). The scarring of acne can also be treated. Your doctor can tell you about various ways available to treat acne scars.

  • Pits and depressions left in the skin from acne scarring can be treated with a "skin-sanding" procedure called dermabrasion, chemical peels, and occasionally with tissue fillers.
  • Bumpy scars are often treated with injections of an intralesional steroid.
  • Lasers can be used in treating scars, but they can be expensive.

Acne Pictures

Hair follicle.
Hair follicle.

Comedones (blackheads and whiteheads).
Comedones (blackheads and whiteheads).

Papules, pustules (zits).
Papules, pustules (zits).

Acne nodules.
Acne nodules.

Reviewed on 2/16/2022
Medically reviewed by Norman Levine, MD; American Board of Dermatology


Knutsen-Larson, S. A.L. Dawson, C.A. Dunnick, and R.P. Dellavalle. "Acne Vulgaris: Pathogenesis, Treatment, and Needs Assessment." Dermatol Clin 30 (2012): 99-106.

Titus, Stephen, and Joshua Hodge. "Diagnosis and Treatment of Acne." American Family Physician 86.8 Oct. 15, 2012: 734-740.