Nonallergic comorbidities of atopic dermatitis

Recognizing the whole spectrum of comorbidities related to atopic dermatitis (AD) is prerequisite for adequate, patient-centered care. Based on systematic reviews (SRs) and published case-control studies, the current evidence on nonallergic comorbidities of AD is summarized. A comprehensive systematic literature search was performed in Medline and Embase (Search period: through 15 November 2014). In total, nine systematic reviews were included. Six reviews investigating the association between AD and cancer suggested a decreased risk of glioma, meningioma, and acute lymphoblastic leukemia in patients with current or previous AD. One SR reported a consistent positive association of AD with attention deficit hyperactivity disorder. In comparison, two SRs focusing on the relationship between AD and diabetes mellitus type 1 and multiple sclerosis showed that there is no evidence supporting an association. A further screening of individual observational studies concerning immunological and psychiatric diseases pointed out that AD seems to be a significant risk factor for Crohn's disease, affective, schizophrenic, and behavior disorders. Further longitudinal studies are needed to verify the existence of causal relationships. Interdisciplinary working groups are desirable to investigate explanations for genetic and physiologic mechanisms of described associations between AD and nonallergic comorbidities.