TY - CHAP M1 - Book, Section TI - Alopecia Areata A1 - Otberg, Nina A1 - Shapiro, Jerry A2 - Kang, Sewon A2 - Amagai, Masayuki A2 - Bruckner, Anna L. A2 - Enk, Alexander H. A2 - Margolis, David J. A2 - McMichael, Amy J. A2 - Orringer, Jeffrey S. PY - 2019 T2 - Fitzpatrick's Dermatology, 9e AB - AT-A-GLANCEAlopecia areata is a nonscarring hair disorder.It occurs in both genders equally and can affect every age group, although incidence at in younger age groups is higher.It is the most common form of hair loss in children. Clinically, it presents with well-demarcated round or oval bald spots on the scalp or other parts of the body.Of patients with alopecia areata, 5% develop hair loss of their entire scalp hair (alopecia areata totalis) and 1% develop alopecia areata universalis (loss of total body hair).Nail changes include pitting or sandpaper nails.Alopecia areata is thought to be an autoimmune disease with a possible hereditary component.In general, alopecia areata is a medically friendly condition, but it can coexist with other autoimmune disorders such as Hashimoto thyroiditis and vitiligo. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - dermatology.mhmedical.com/content.aspx?aid=1161326095 ER -