Symptoms and causes

Symptoms

Keratosis pilaris can occur at any age, but it's more common in young children. Signs and symptoms include:

  • Painless tiny bumps, typically on the upper arms, thighs, cheeks or buttocks
  • Dry, rough skin in the areas with bumps
  • Worsening when seasonal changes cause low humidity and skin tends to be drier
  • Sandpaper-like bumps resembling goose flesh

When to see a doctor

Treatment for keratosis pilaris usually isn't necessary. But if you're concerned about the appearance of your or your child's skin, consult your family doctor or a specialist in skin diseases (dermatologist). He or she can often make a diagnosis by examining the skin and the characteristic scaly bumps.

Causes

Keratosis pilaris results from the buildup of keratin — a hard protein that protects skin from harmful substances and infection. The keratin forms a scaly plug that blocks the opening of the hair follicle. Usually many plugs form, causing patches of rough, bumpy skin.

No one knows exactly why keratin builds up. But it may occur in association with genetic diseases or with other skin conditions, such as atopic dermatitis. Dry skin tends to worsen this condition.

Jan. 05, 2016
References
  1. AskMayoExpert. Keratosis pilaris. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.
  2. Keratosis pilaris. American Osteopathic College of Dermatology. http://www.aocd.org/skin/dermatologic_diseases/keratosis_pilaris.html. Accessed Nov. 4, 2015.
  3. Keratosis pilaris. Merck Manual Professional Version. http://www.merckmanuals.com/professional/print/dermatologic_disorders/cornification_disorders/keratosis_pilaris.html. Accessed Nov. 4, 2015.
  4. Keratosis pilaris. American Academy of Dermatology. https://www.aad.org/dermatology-a-to-z/diseases-and-treatments/i---l/keratosis-pilaris/who-gets-causes. Accessed Nov. 4, 2015.
  5. Goldsmith LA, et al., eds. Keratosis pilaris and other inflammatory follicular keratotic syndromes. In: Fitzpatrick's Dermatology in General Medicine. 8th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com. Accessed Nov. 4, 2015.
  6. Dermatologists' top 10 tips for relieving dry skin. American Academy of Dermatology. https://www.aad.org/dermatology-a-to-z/health-and-beauty/general-skin-care/dry-skin-tips. Accessed Nov. 4, 2015.
  7. Retin-A. U.S. Food and Drug Administration. http://www.accessdata.fda.gov. Accessed Nov. 5, 2015.
  8. Goldsmith LA, et al., eds. Epidermal growth and differentiation. In: Fitzpatrick's Dermatology in General Medicine. 8th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com. Accessed Nov. 5, 2015.