Keratosis pilaris (also known as keratosis follicularis, lichen pilaris and follicular keratosis) is a harmless, non-contagious dermatosis characterised by the presence of small, rough bumps on the skin (papules), particularly on the face, buttocks, thighs and back of the arms. But it can also affect the face, particularly in children. Small pimples appear, and the skin becomes rough and uneven, giving it a "chicken-skin" appearance. It is caused by severe skin dryness and an abnormal build-up of keratin in the hair follicles. The follicles become clogged with horny plugs, giving the skin an irregular appearance.
Keratosis pilaris affects almost 25% of French people, and is one of the most common skin diseases. It affects children, teenagers and young adults in particular, and women more often than men. From the age of 30, it diminishes. It may intensify with the seasons, with more papules in winter and fewer in summer.
The diagnosis of keratosis pilaris is purely clinical and based on observation of the lesions.

















