Contact allergy to idoxuridine

Abstract

A total of 45 of 60 patients with herpes zoster previously treated with topical idoxuridine 5-40% in dimethylsulfoxide were patch-tested 2 yr later with idoxuridine 0.5% and 5% in petrolatum. Three (7%) showed positive reactions. Idoxuridine is considered a weak sensitizer, but in strong concentrations and in active solvents, which increases absorption, there seems to be a risk of sensitization.