Moderate-to-severe atopic dermatitis (AD) generates a considerable consumption of healthcare resources and significant economic consequences for the patients and their families, healthcare systems (NHS) and society. Several studies on the burden of AD in paediatric patients are available in literature, while data in adults is scant. The purpose of this study was to estimate the direct and indirect costs of moderate to severe AD in adult patients in Italy.Patients with Eczema Area and Severity Index (EASI) score >20 were included in a multicentre, observational study conducted in six outpatient dermatology clinics throughout the national territory. Data were retrospectively gathered through a case report form investigating healthcare resources consumption, out-of-pocket expenses and patients' and caregivers' productivity loss. Descriptive statistics was used to illustrate data. Univariate generalized linear model with gamma distribution and identity function link was used to describe association between costs and disease severity.A total of 50 patients with a diagnosis of moderate-to-severe DA (EASI score ≥ 20), equal to 89% of the total, were included in the analysis. The total annual burden of the disease, direct and indirect costs, amounted to € 4,284 per patient; 19.3% accounted for direct medical costs, 19.9% for direct non-medical and 60.8% for indirect costs due to productivity loss.Moderate-to-severe AD in adults represents an important cost for the society imposing a high financial burden for the NHS, but even more for patients and caregivers. Results from this study may support identification of potential factors impacting on the choice of new therapeutic options to improve the clinical and economic management of this devastating disease.