Epidemiological Assessments of Skin Outcomes in the Nurses' Health Studies.

Objectives: To review the contribution of the Nurses' Health Studies (NHSs) to identifying epidemiological factors associated with multiple skin diseases, including skin cancer, psoriasis, and other inflammatory and autoimmune skin diseases.

Methods: We carried out a narrative review of NHS articles published between 1976 and 2016.

Results: The NHSs have identified environmental and lifestyle factors related to psoriasis, supporting obesity and smoking as psoriasis risk factors; associations between psoriasis and diabetes, myocardial infarction, and Crohn's disease, supporting psoriasis as a systemic disorder; and associations of pigmentary traits, ultraviolet radiation, and lifestyle factors such as citrus consumption with risk of skin cancer. Genetic studies have identified novel genetic loci for skin pigmentation (e.g., IRF4, SLC24A4, NID1, and EDNRB) and skin cancer (e.g., TET2 and HERC2-OCA2). Work continues on highly prevalent but less studied skin conditions such as rosacea, acne, and atopic dermatitis. The NHS results have influenced public health policies on indoor tanning devices.

Conclusions: The NHSs have provided invaluable resources on skin disease population science and contributed to the etiological understanding of multiple skin disorders.