Background Patients with atopic dermatitis (AD) are susceptible to infectious and inflammatory cutaneous comorbidities. Objective The aim of the study was to describe the prevalence of cutaneous comorbidities associated with AD, including their relationship with AD severity. Methods A retrospective cross-sectional analysis was performed using the Israeli Maccabi Healthcare Services database. Prevalent AD cases on December 31, 2017, were diagnosed with AD at any time since 1998 and had 1 or more recent (2013-2017) AD diagnoses. Dispensed AD treatments within 5 or fewer years served as a surrogate for AD severity. Cutaneous comorbidities in AD cases were compared with non-AD controls matched 1:1 on age, sex, and residential area. Among adults, comorbidities were compared across AD severity using multinomial logistic regression. Results The eligible population included 94,483 patients with mild (57.7%), moderate (36.2%), or severe (6.1%) AD, and 94,483 matched non-AD controls. Skin infections, inflammatory skin conditions, cutaneous manifestations of AD, and sweat gland disorders were more prevalent (P < 0.001) in patients with AD than in controls. Most cutaneous comorbidities that were more prevalent in adult patients with AD were also significantly (P < 0.001) associated with AD severity. Conclusions This study suggests that AD is associated with many infectious and inflammatory cutaneous comorbidities and highlights the relationship between AD severity and comorbidity prevalence.