Contact Photosensitivity Patterns to Halogenated Salicylanilides

Abstract

Photocontact dermatitis was observed in 32 patients who had been exposed to brominated salicylanilides or other closely related chemicals used as antimicrobial agents in soaps. Patterns of cross-reactivity between tribromsalan, dibromsalan, metabromsalan, TCSA, bithional, hexachlorophene, and trichlorcarbanilide were assessed. Action spectrum studies using monochromatic radiation indicated a peak reactivity in the 3,600Angstrom range. Twelve of the 32 patients were found to be persistent light reactors. Their clinical characteristics, abnormal reaction to sunburn radiation, and course are described. Contact photosensitivity was induced in Hartley strain albino guinea pigs with both TCSA and tribromsalan. Patterns of cross-reactivity were assessed and found to be similar to those observed in man. Preliminary data concerning successful passive transfer in guinea pigs of photocontact hypersensitivity using mononuclear peritoneal exudates is presented.