Abstract The prevalence of active atopic dermatitis (AD) in adults in the UK according to disease severity shows variability. This study evaluated disease prevalence and treatment patterns among the adult UK population with AD. Data were obtained from the Clinical Practice Research Datalink (CPRD) database. Adults with active AD were identified by an AD-related prescription or general practitioner visit within the same calendar year. Prevalence was defined as the number of patients with active AD on 1 January of each year as a percentage of the number of adults in the CPRD population on that date. Moderate-to-severe disease was classified as either referral to a specialist or prescription(s) for topical calcineurin inhibitors, phototherapy, or systemic treatment. Patient characteristics and treatment and referral patterns were analysed for patients with active AD in 2019. The overall prevalence of AD was stable at 2.4% per year during the period 2015–2019. In 2019, mean patient age (± standard deviation) was 52.6 ± 21.0 years, 58.2% of patients were female and mean disease duration was 9.4 ± 5.9 years. The most prescribed treatment was topical corticosteroids, in 78.5% of patients. 36.7% of patients with moderate-to-severe AD were prescribed systemic agents and 59.8% (vs. 32.3% of patients with mild AD) were referred to any secondary care or specialist treatment. The prevalence of active AD in the adult UK population was stable over the 5-year period (2015–2019) and was comparable to estimates from similar studies based on UK primary healthcare records.