Keratosis pilaris (KP) is a common hereditary condition that is more common in women than in men. It appears as rough bumps on the skin, mainly on the back and outer sides of the upper arms. Cheeks, thighs and the tops of the legs can also be affected. KP affects an estimated 40% of the adult population and approximately 50-80% of all adolescents. Individuals susceptible to this often have a personal or family history of hay fever, asthma, or allergies, as well as atopic eczema.
KP occurs when the body produces excess keratin, a natural protein in the skin. The excess keratin surrounds the hair follicles in the pore, which causes the formation of the small, rough bumps that are seldom sore or itchy. Though people with KP experience this condition year-round, it can worsen during the colder months, when moisture levels in the air are lower. During this time, the condition is apt to look and feel more pronounced in both color and texture.