Keratosis pilaris

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

Keratosis pilaris is benign, self-limiting, and often disappears with age. It is more common in patients with atopic dermatitis (eczema) and seems to run in families.

In mild cases, small bumps, similar in appearance to “goose bumps,” are found on the backs of the upper arms. The texture is that of very coarse sandpaper.

Bumps may also appear on the buttocks and thighs. Less commonly, lesions appear on the face and may be mistaken for acne.

Individual lesions consist of a small, skin-colored papules that form within hair openings. The condition is generally worse in winter and often clears in the summer.


  • fine, bumpy texture to skin over the outer upper arm and thigh or elsewhere  
  • bumps the size of a grain of sand and skin colored  
  • slight pinkness may be seen around some bumps

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

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 likely.

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.

Johns Hopkins patient information

Last revised: December 3, 2012
by Martin A. Harms, M.D.

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