Posted in Web Alopecia Areata Guide: Causes, Symptoms and Treatment Options April 19, 2020 Alopecia areata is a skin disorder that causes hair loss, usually in patches, most often on the scalp. Usually, the bald patches appear suddenly and affect only a limited area. The hair grows back within 12 months or less. https://www.drugs.com/health-guide/alopecia-areata.html