What is the cause of acne?

Acne is the most common skin condition that people experience. Most people develop acne to some degree during their lifetime. Though it primarily affects teenagers undergoing hormonal changes, many people will develop acne as adults. Acne might be mild (few, occasional pimples), moderate (inflammatory papules), or severe (nodules and cysts). Scarring can occur. Treatment depends on the severity of the condition.


Acne is primarily a hormonal condition driven by male hormones, which typically become active during the teenage years. Sensitivity to such hormones — combined with surface (skin) bacteria and lipids (fatty acids) within sebaceous (oil) glands — yields acne. Common sites for acne are the face, chest, shoulders, and back — the sites of oil glands.

The first lesion in acne is a comedone or clogged pore (whiteheads, blackheads). These can become inflamed and progress to papules and pustules (small bumps), nodules, and cysts. Larger nodules and cysts and popping of pimples often lead to scarring.

Certain conditions can aggravate acne.

  • Fluctuating hormone levels around the time of menses (menstruation)
  • Manipulating (picking/prodding) acne lesions
  • Blocking clothing and headgear, such as hats and sports helmets
  • Air pollution and certain weather conditions, especially high humidity

What is the treatment for acne?

Only three medicines have proven to be effective for the treatment of acne: benzoyl peroxide, retinoids, and antibiotics. These medications target the different factors that contribute to acne. Most patients require at least one or two agents, depending on disease severity.

  • Benzoyl peroxide is available as an over-the-counter product (such as Clearasil®, Stridex®, PanOxyl®) available as a leave-on gel or wash. It targets surface bacteria, which often aggravate acne. Irritation (dryness) is a common side effect. Lower concentrations and wash formulations are less irritating.
  • Retinoids (vitamin A derivatives): such as Retin-A®, Tazorac®, and Differin® ,which is available over the counter — "break up" comedones (blackheads and whiteheads) and help to prevent clogged pores, the first lesions of acne. Most patients are candidates for retinoid therapy. These medications are not spot treatments and must be used on the entire area of skin affected by acne to prevent the formation of new acne bumps. The most common side effect is irritation which usually improves with moisturization and time on the medication.
  • Antibiotics, either topically applied to the skin (clindamycin, erythromycin) or taken by mouth (tetracycline and its derivatives) control surface bacteria that aggravate and often foster inflammation in acne. Antibiotics are more effective when combined with benzoyl peroxide which prevents antibiotic resistance, or retinoids.

The oral retinoid isotretinoin (Accutane®) is reserved for those patients with severe (nodular or cystic) disease or those with scarring. Accutane shrinks the size of oil glands, the anatomic origin of acne. Without active, plump oil glands, acne actively diminishes.

Because it is a medication taken by mouth, there are more possible side effects than with topical treatments. All patients will experience skin dryness. Less commonly, patients can have elevated blood lipids or liver enzymes.

Women of childbearing age must practice birth control before and during treatment with Accutane®, and for several months afterward because of the risk of devastating birth defects. Because of these risks, the use of Accutane® requires regular lab testing (lipids, pregnancy tests) and follow-up during the medication course, which usually lasts 5 or six months.

Hormone therapy is helpful for some women with acne, especially for those that flare with their menses or those with signs and symptoms (irregular periods, thinning hair) of androgen (male hormone) excess. The hormone therapy consists of low-dose estrogen and progesterone (birth control pills) or a medication called spironolactone that blocks the effect of male hormones at the level of the hair follicle and oil gland.


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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 3/22/2017…#12233