Keratosis pilaris is a common skin condition in which keratin, a protein in the skin, forms hard plugs within hair follicles.

Causes, incidence, and risk factors

In mild cases, small bumps, similar in appearance to "goose bumps," experienced when cold or frightened, are found on the posterior portion of the upper arms. The texture is that of very coarse sandpaper. Bumps may also appear on the buttocks and thighs. Less commonly, lesions on the face are found, often mistaken for acne. Individual lesions consist of a small, skin-colored papules which form within hair openings. The condition is generally worse in winter and often clears in the summer. The condition is benign , self-limiting, and often disappears with increasing age. It is more common in patients with atopic dermatitis (eczema) and seems to run in families.

Signs and tests

Physical examination is usually sufficient for your health care provider to make this diagnosis. Testing is usually not necessary.

Treatment

Moisturizing lotions are often soothing and may help the appearance of the skin. Topical treatment with medications containing urea, lactic acid, Retin A (tretinoin), or Vitamin D may be recommended by your physician. However, improvement often takes months and recurrence is expected after cessation of therapy.

Expectations (prognosis)

Keratosis pilaris may fade slowly with age.

Calling your health care provider

Call for an appointment with your health care provider (or discuss the condition during a routine visit) if you suspect that you have keratosis pilaris and the condition does not respond to use of over-the-counter moisturizing lotions.