Keratosis pilaris (KP) describes bumpy, dry skin caused by hair follicles becoming plugged by dry skin cells. It can occur at any age or location on the body, but it is particularly common on the upper arms of teenagers and adults, and on the cheeks of infants.
A KP rash seldom itches, is never painful and is similar in texture to coarse sandpaper. It is more common in people with dry skin, such as people with atopic dermatitis (eczema)
. It tends to arise or worsen during winter months when the air is dry.