There are strong data on the relationship between dietary patterns and skin conditions. This article provides an introduction for dermatologists on the role of diet in 3 common skin conditions: acne vulgaris, psoriasis, and atopic dermatitis (AD). High glycemic index foods are associated with acne vulgaris. Psoriasis is associated with obesity and weight loss, and improved dietary patterns may improve cutaneous disease. Children with AD are at higher risk for food allergies, and a small subset may experience flares in relationship to non-IgE-mediated food allergies, though there is a need for further research to clarify which patient subsets require allergen testing and food avoidance.