The effect of UV-irradiation on viral infections of the skin.

The effect on the skin of exposure to relatively small doses of ultraviolet light has long been thought beneficial and socially desirable, leading to a 'healthy tan'. However it is less well known that similar (if not smaller) doses of UV-B radiation can have transient but profound depressive effects on the immune response to antigens or pathogens encountered by the skin. The result of this on the immunopathology of both primary and recurrent episodes of persistent viral infections of the epidermis is discussed.