Photoimmunology is the study of the effects of nonionizing radiation on normal and abnormal immune function, a meeting point of the fields of photobiology and immunology. The area is of interest to dermatologists for several reasons: most nonionizing radiation that reaches the immune system traverses the skin; a number of photobiological disorders of the skin are thought to have an immune basis; dermatologists largely control therapeutic exposure to nonionizing radiation; and dermatologists see many of the undesirable effects of environmental exposure to such radiation and some of these may have an immune pathogenesis.

Until recent years, most basic research in photoimmunology has been concerned with the effects of UVC (254 nm) radiation in vitro. It has been demonstrated that such radiation can influence the function of antibodies, decrease the viability and alter the function of lymphocytes, and increase the antigenicity of DNA. Recently, a few reports have been published on