BackgroundAtopic dermatitis (AD) is a common chronic skin disorder, which may persist into adulthood; however, the prevalence of comorbidities in patients with AD is not well characterized. AD is considered a systemic disorder like psoriasis, which has raised a need for data on the comorbidity profile of patients with AD, to assess the potential risks, benefits, and complications in management of patients with AD. We described the occurrence of medical and psychiatric comorbidities and associated risk factors in adults with AD compared with psoriasis and the general population. MethodsAll Danish individuals aged 18 years with a hospital (inpatient or ambulatory) diagnosis of AD or psoriasis during the study period (January 1, 1995-December 31, 2012) were linked in administrative registers. ResultsOverall, prevalence of smoking and alcohol abuse was higher among patients with AD than the general population, but lower than psoriasis patients. Similarly, patients with AD had more risk factors and higher prevalence of comorbidity than the general population, but lower prevalence and reduced risk compared to psoriasis patients, except for use of anxiolytics, which was higher in severe AD. Prevalence of diabetes was lower in AD than psoriasis patients as well as general population controls. ConclusionsDespite an increased risk of various medical and psychiatric comorbidities compared to general population controls, adult patients with AD had markedly lower prevalence of cardiovascular disease than psoriasis patients. However, prevalence of psychiatric comorbidity and tobacco smoking was alarmingly high in severe patients with AD, which might be target for intervention in patient management.