What is alopecia areata? Alopecia areata is a disease that causes hair loss. In alopecia areata, the immune system attacks the structures in skin that form hair (hair follicles). Alopecia areata usually affects the head and face, though hair can be lost from any part of the body. Hair typically falls out in small, round patches about the size of a quarter. In some cases, hair loss is more extensive.
Psoriasis is a chronic skin condition characterized by itchy red patches and silvery scales, usually on the elbows, knees or scalp. It affects about 2 percent of Americans, and is sometimes associated with other health problems, such as arthritis, diabetes and heart disease. The causes are not fully understood, but the condition is related to an abnormal immune assault on skin cells that triggers inflammation. Scientists have been trying to understand the molecular details of what causes psoriasis. Now, two studies funded in part by the NIH’s National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) and published in