• Three of four subjects demonstrated a phototoxic reaction following topically applied 25% sulfisoxazole diolamine ointment and exposure to UV light. The histopathologic features of a biopsy specimen taken from the site of a positive response were consistent with phototoxicity and not photoallergy. This study indicates that sulfisoxazole has a phototoxic potential following topical application.
Flach AJ, Peterson JS, Mathias CGT. Photosensitivity to Topically Applied Sulfisoxazole OintmentEvidence for a Phototoxic Reaction. Arch Ophthalmol. 1982;100(8):1286-1287. doi:10.1001/archopht.1982.01030040264013