Photoallergy to fenticlor (S7) in three patients and to Multifungin in four patients is reported. Fenticlor (bis[2-hydroxy-5-chlorphenyl] sulfide), is related chemically to bithionol. Multifungin (5-bromo-4′-chlorosalicylanilide), is related chemically to tribromosalicylanilide. Fenticlor and Multifungin are used as antifungal applications in Australia.
Photo-patch tests were carried out using direct sunlight. Cross-sensitization between fenticlor and hexachlorophene was demonstrated and there was also evidence to suggest crosssensitization between fenticlor and bithionol. Cross-sensitization between Multifungin and tribromosalicylanilide was found in all four cases. There was a close similarity between the patchtest responses to these two chemicals.
Both localized and generalized photoallergies were noted in the same patient. The localized sensitivity might last for several months. The generalized sensitivity was transient. The possible mechanisms producing these responses are discussed in relation to the clinical findings, with emphasis placed upon the role that the abundant Australian sunshine must play.
Burry JN. Photoallergies to Fenticlor and Multifungin. Arch Dermatol. 1967;95(3):287-291. doi:10.1001/archderm.1967.01600330045007