Keratosis Pilaris (KP) is a very common skin disorder characterized by the appearance of rough bumps on the back and outer sides of the upper arms. In some instances, Keratosis Pilaris can also appear on the thighs, buttocks or virtually anywhere on the body. Keratosis Pilaris is typified by numerous tiny rough spots in the affected area. Each of the Keratosis Pilaris bumps appears to resemble a goosebump both in sight and touch. However, the Keratosis Pilaris bumps are each a clogged or plugged follicle. Many times, the skin surrounding the follicles might be slightly irritated, causing the Keratosis Pilaris to look like a red rash. Keratosis Pilaris is completely harmless and has no unhealthy affects on the affected area. But, the condition can be unattractive.

Keratosis Pilaris tends to be more severe during the winter months or other times of low humidity when skin dries out. Another contributing factor to the incidence of Keratosis Pilaris is the climate. Areas where relative humidity is low have a higher incidence of Keratosis Pilaris. The reason for the increase occurrence of Keratosis Pilaris in the above described conditions is that the dry air contributes dry flaky skin condition. The bumps of Keratosis Pilaris result from the manner in which dry flaking scales of skin are shed from the outer skin around Keratosis Pilaris affected hair follicles. With the Keratosis Pilaris affected hair follicles, the outer skin scales become adherent and do not shed easily. This fact is known as abnormal Keratinization or Hyperkeratinization.

When Keratosis Pilaris occurs on the face (i.e. cheeks), in almost all cases the affected area is not only rough with tiny bumps but it is also is red and irritated. The red color of the skin caused by Facial Keratosis Pilaris gives it the clinical name of Keratosis Pilaris Rubra Faceii. Another variant on the face, called "Keratosis Pilaris Atrophicans Faciei", causes an unsightly atrophy of the skin to develop. When the outer eyebrows are affected the condition is known as "ulerythema ophryogenes". Face occurrences often affect babies where it tends to be most obvious on the cheeks. FacialKeratosis Pilaris as well as Karratosis Pilaris in other areas of the body is very common in babies and young children; however as the body ages the occurrence of Keratosis Pilaris becomes more and more uncommon. Keratosis Pilaris is rarely found in elderly people.