Treatment of Atopic Dermatitis and Alopecia Areata With Abrocitinib in Individuals With Down Syndrome

This is a single-center, open-label, basket phase 2b trial that will enroll Down Syndrome (DS) participants with at least one inflammatory skin condition (Atopic Dermatitis (AD) and/or Alopecia Areata (AA)). Patients will receive Abrocitinib 100 mg daily for 12 weeks. Responders (defined as achieving Eczema Area and Severity Index (EASI) 75 response for AD, or SALT \<= 20 for AA) will be kept on this dose, and non-responders based on these definitions, will initiate 200 mg daily for another 12 weeks. All AD and AA patients will be maintained on the respective dose of Abrocitinib from Week 24 through week 60.