Recent epidemiological studies found the US prevalence of atopic dermatitis in adults to be approximately 7%. In particular, one in four adults with atopic dermatitis report adult onset of their disease. Adult-onset compared to child-onset atopic dermatitis is associated with distinct risk factors, lesional distribution and morphology, associated signs, genetics, and comorbidities. Adult-onset atopic dermatitis is a clinical diagnosis, and must be distinguished from other entities in the differential diagnosis, e.g., allergic contact dermatitis and cutaneous T-cell lymphoma. Further research is necessary to better understand the pathogenesis and optimal treatment approaches in adult-onset/recurrent atopic dermatitis.