Background: Photoallergy to ketoprofen and cross reactivity of ketoprofen with diphenylketones are well known; here are some cases of photoreaction to ketoprofen and unusual substances.
Patients and methods: Eleven photoallergic to ketoprofen patients were photo patch tested with Ketum(R), ketoprofen, oxybenzone, tiaprofenic acid, fenofibrate, and also chlorphenesin, sunscreen series, and photobiologists series (without lichen mix and benzocaine). We performed tests at day 0, we irradiated them with UVA at day 2, and control series remained closed. We performed readings at day 3 and 4 according to ICDRG's recommendations.
Results: Nine tested patients had positive reactions to the irradiated tests with no expected allergens: fenticlor (9 cases), halogenated salicylanilides (4 cases), dibenzoylmethane (3 cases) and cinnamate (1 case).
Discussion: The mechanism of these unusual photosensitizations is discussed. These cases show that it is important to test sunscreen series and photobiologists series in patients photoallergic to ketoprofen.