An Observational Study to Assess Change in Disease Activity and Use of Upadacitinib Tablets in Adolescent and Adult Participants With Moderate to Severe Atopic Dermatitis in Real World

Inclusion Criteria: * Physician confirmed diagnosis of atopic dermatitis or atopic eczema at baseline. * Symptom onset ≥1 year prior to baseline. * Initiation of upadacitinib treatment for AD is indicated and prescribed per local label. * The decision to prescribe upadacitinib is made prior to and independently of study participation. * Participants who can understand and who are willing and able to complete the questionnaires, with parental support as required for adolescents. * Participants (or legal representatives for adolescents) with a smartphone/tablet with internet access and willing to download the dedicated application to complete the questionnaires via this application. * Participants (and legal representatives for adolescents) who have been informed verbally and in writing about this study before inclusion, and who do not object to their data being processed. * Participants (and legal representatives for adolescents) able to understand and communicate with the investigator. Exclusion Criteria: * Participation in a clinical trial assessing an investigational drug, concurrently or within the last 30 days. * Prior treatment with upadacitinib.