About 60% of all patients with AD are adults. However, the prevalence and incidence is significantly higher in childhood and adolescence. Some children, adolescents and adults with moderate-to-severe AD cannot be sufficiently controlled with topical treatments alone and require intermittent or continuous treatment with systemic immunomodulating agents or UV-therapy. Systematic reviews indicate that although several different interventions for moderate-to-severe AD have been studied in clinical trials, strong recommendations are only possible for Dupilumab in adults and the short-term use of cyclosporin A (CSA). Pharmaceutical treatment of patients suffering from AE is diverse and frequently not in line with the current guidelines (for example S2-guideline in Germany). Large head-to-head trials are missing so that long-term effectiveness of systemic interventions for moderate-to-severe AD is speculative. In this situation, clinical registries can provide valuable information for evidence-based clinical decision making. Extension of TREATgermany to children and adolescents is necessary as * moderate-to-severe AD is frequent in this age group, but the effectiveness of existing topical and systemic agents in the routine care setting on clinical severity, patient-reported outcomes, and the course of AD and associated atopic and non-atopic comorbidities over time is still poorly understood * it is unclear how many children and adolescents cannot be effectively controlled with the avoidance of trigger factors, patient education, and topical anti-inflammatory treatment alone * innovative agents will become available for these age groups within the next years and reference data will be necessary to evaluate their effectiveness and indication criteria * adequate evidence regarding patient needs in children and adolescents with moderate-to-severe AD is urgently needed to provide value-based healthcare for this vulnerable patient group * Best-practice models of transition from adolescent to adult care of patients with moderate-to-severe AD do not exist yet, but constitute a prerequisite for the establishment of efficient patient care