Overview of Keratosis Pilaris

Keratosis pilaris is a condition in which the hair follicles become blocked with hair and dead cells from the outermost layer of skin (epidermis). The follicles redden and inflame causing bumps (papules) to develop. The papules of keratosis pilaris usually occur on the upper arms and thighs, but also appear on the face, back, and buttocks.

Keratosis Pilaris Causes and Risk Factors

Keratosis pilaris (KP) is a hereditary disorder. One can inherit it from one or both parents. KP stems from overreproduction of keratinocytes, the cells that manufacture the protein keratin, an important skin component (called hyperkeratosis). Some researchers describe KP as one of a whole spectrum of disorders, rather than as an independent disease.

KP is more prevalent among children and adolescents and less common in adults. It seems to improve after puberty. Individuals with dry skin and eczema (also called dermatitis; a common skin disorder) tend to have more severe cases. The condition improves during warm summer months and worsens during the winter.

Keratosis Pilaris Signs and Symptoms

The signs of keratosis pilaris are the papules that typically appear on the upper arms and thighs, and sometimes on the back, face, and buttocks. Papules re-form after they have been removed.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 31 Aug 2000

Last Modified: 15 Sep 2015