CorEvitas International Adolescent Alopecia Areata (AA) Drug Safety and Effectiveness Registry

Inclusion Criteria: To be eligible to participate in this registry, an individual must meet all the following criteria: 1. Has ever been diagnosed with severe AA by a dermatologist or a qualified dermatology provider. 2. Is 12-17 years of age at the time of enrollment. 3. Is willing to provide consent/assent for participation in the registry. 4. Has been prescribed a new commercially available advanced therapy and/or conventional systemic therapy for the treatment of severe AA in adolescents in the context of routine clinical care that is consistent with local prescribing guidelines and/or regulations for the country where the site is located. A new therapy is a medication that the subject has never taken before. 1. At the time of registry enrollment OR 2. Within 6 months prior to registry enrollment In the opinion of the treating provider, is deemed a candidate for treatment with a commercially available advanced therapy and/or conventional systemic therapy for the treatment of severe AA in adolescents but has not received nor is planning to initiate treatment at the time of registry enrollment. Exclusion Criteria: An individual who meets any of the following criteria will be excluded from participation in the registry: 1. Is participating or planning to participate in a blinded clinical trial for any investigational medication. 2. Is unwilling or unable to provide standing height measurements.