Photodermatitis for the Allergist.

Abstract

The photodermatoses represent a group of disorders of sensitivity to light that continue to pose difficulties in diagnosis and management. Photodermatoses are of interest to allergists because many photosensitive skin disorders have immunologic underpinnings, and patients often present to clinic complaining of "allergy" to the sun. We provide a concise reference for allergists on the clinical recognition and management of photodermatitis. New developments in the understanding of immunomodulatory effects of light have demonstrated normally immunosuppressive responses in the skin to light exposure, and a blunted immunosuppressive response in the pathogenesis of many photodermatoses. Vitamin D plays an important role in immunomodulation and itself may be affected by photodermatoses due to the impact of photoprotective treatment strategies on circulating vitamin D levels. The elucidation of the immunological basis of many photodermatoses may provide guidance for developing new treatment modalities. Further research is necessary to determine the optimal management of vitamin D metabolism in patients with photodermatoses.