Interaction of methotrexate and betamethasone with experimental phototoxic inflammation to PUVA (Psoralen and UVA) in mice.

The influence of methotrexate and of betamethasone on a following phototoxic reaction to 8-methoxypsoralen and long-wave ultraviolet light (PUVA) was studied in the mouse. High PUVA doses were not influenced by the two drugs tested. Both methotrexate and betamethasone tended to diminish the PUVA response when psoralen was given in a medium dose.