Keratosis pilaris (ker-uh-TOE-sis pih-LAIR-is) is a harmless skin condition that causes dry, rough patches and tiny bumps, often on the upper arms, thighs, cheeks or buttocks. The bumps usually don't hurt or itch.

Keratosis pilaris is often considered a common variant of skin. It can't be cured or prevented. But you can treat it with moisturizers and prescription creams to help improve how the skin looks. The condition usually disappears by age 30.


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

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

When to see a doctor

Treatment for keratosis pilaris usually isn't needed. But if you're concerned about your or your child's skin, consult your health care provider or a specialist in skin conditions (dermatologist).


Keratosis pilaris is caused by the buildup of keratin — a hard protein that protects skin from harmful substances and infection. The keratin blocks the opening of hair follicles, causing patches of rough, bumpy skin.

It's not clear why keratin builds up in people with keratosis pilaris. It might happen along with a genetic disease or skin conditions such as atopic dermatitis. Dry skin tends to make keratosis pilaris worse.