Tiaprofenic acid induced photosensitivity.

45 patients (34 patients with PLE, 11 with phototoxic or photoallergic dermatitis) were photopatch tested to tiaprofenic acid. In 23 patients (51%), phototoxic reactions were found. Positive reactions appeared within 0.5 to 48 h of irradiation. Although each patient was irradiated with 2 different UVA light sources, with significantly different energy outputs (10 J/cm2 against 72 J/cm2), the intensity and duration of positive reactions was virtually the same. We found a considerably higher rate of positive reactions than other investigators, independent of the light energy delivered. None of the patients gave a history of previous tiaprofenic acid exposure.