Dynamics of ultraviolet dermatitis as studied with the mouse tail technique.

Time course and dose-response relationships have been studied for medium-wave ultraviolet radiation (UVB) in the mouse by measuring the inflammatory oedema of tail tissue. The time course was shown to be dose dependent, larger doses peaking earlier than smaller ones. For intermediate doses the reaction culminated after 48 h. Dose-response curves were sigmoid-shaped with good linear correlation in the region of maximal slope. The dose-response curve was studied at varying intervals after irradiation and the relationship could be shown to be time dependent. UVB differs in some of these respects from phototoxic reactions to chlorpromazine and 8-methoxypsoralen.