Phototoxic polyacetylenes and their thiophene derivatives. (Effects on human skin).

Polyacetylenes and their thiophene derivatives were tested for their effects on human skin. Topically applied alpha-terthienyl evoked bi-phasic phototoxic dermatitis and the appearance of 'sunburn' cells in human epidermis. None of 11 polyacetylenes had the same effect although they mimicked alpha-terthienyl in their phototoxic effects on Candida albicans and certain pathogenic microorganisms. The UV-mediated antibiotic activity of the compounds and their apparent lack of phototoxicity towards the skin suggest a potential topical therapeutic role for them in yeast, fungal and bacterial infections and light-responsive dermatoses. Their topical sensitizing capacity, however, has not yet been studied.