By Gary M. White, MD

Cystic acne

Acne is one of the most common skin conditions. It affects nearly every teenager as well as many young women. It begins in the prepubertal years (e.g., 8 -13 years), peaks around age 16, and for males, usually remits by age 20. Unfortunately for women, the acne may persist well into the 20's and even 30's. Furthermore, some women who had very little to no acne before age 20 may develop acne in adulthood. The peak for women taking isotretinoin in one study was 24 years of age.

P. Acnes Resistance

Twenty years ago, P. acnes was readily killed by erythromycin, clindamycin and the tetracyclines. Unfortunately, after decades of use, widespread antibiotic resistance by P. acnes has emerged. These drugs are much less effective. Thus, acne therapy has shifted to emphasizing the use of benzoyl peroxide, the topical retinoids, and oral isotretinoin.


Early acne consists of comedones of the central face along with oily skin. (An open comedone is a blackhead and a closed comedone is a whitehead). Later, inflammatory papules and pustules develop. It is at this point that scarring may occur. Inflamed nodules occur in severe acne.

Patients often have a hard time not picking, squeezing or excoriating the acne. Unfortunately, aggressive manipulation can lead to scarring or depigmentation. See acne excoriee. Scarring may follow inflammatory acne of any severity. It may appear as a pit, slightly depressed area, or as a hypertrophic scar. See acne scars.

The trunk commonly develops acne lesions, but comedones are few. Inflammatory papules and pustules predominate. Truncal acne is often more resistant to treatment and usually requires oral antibiotics or isotretinoin. In the shower, BP wash/foam applied to wet skin and left on for 2-3 minutes can reduce P. acnes and can have benefit.

Palpation of the acne is recommended. This gives the clinician a sense of the severity, especially in darker-skinned patients where the pigment can hide the inflammation. Individual lesions that persist should be assessed for any linearity or angularity suggesting an acne sinus or for firmness, e.g. hypertrophic scarring.

Several drugs may cause acne including cyclosporin, anticonvulsants and lithium.

Categorization of Acne by age

Acne Type Age Comments
Neonatal Acne 0-6 weeks Very common. Spontaneously remits.
Infantile Acne 0-1 year Uncommon
Middle Acne 1-7 years Very uncommon. Needs hormonal workup.
Preadolescent Acne 7-12 years Uncommon, but no workup needed.
Adolescent Acne 13-19 years The classic teenager with acne.
Adult Acne 20-50 years Very common. Usually a woman.


See acne treatment and acne handout.

Additional Pictures

Acne on the back Acne on the forehead

Acne in a woman.
Acne on the face of a woman

Comedonal acne. A topical retinoid is needed here.
Comedonal acne on the forehead

Excoriations are typical. Sometimes, the acne is not visible, just signs of scratching. See acne excoriee.
Excoriated acne

For more pictures, see acne gallery.


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