Allergic and photoallergic contact dermatitis from ketoprofen: results of (photo) patch testing and follow-up of 42 patients

Background: Photoallergic contact dermatitis from topical ketoprofen (KP), a nonsteroidal anti-inflammatory agent, is a well-known side effect. Objectives: To investigate photo-contact allergic reactions to KP and other nonsteroidal anti-inflammatory drugs (NSAIDs), sunscreens, and fragrance components as well as the presence of prolonged photosensitivity related to it. Patients/Methods: From June 1993 to June 2007, 42 patients were patch tested and photopatch tested with the ingredients of a KP preparation and other relevant substances. A questionnaire was performed in order to determine the importance of prolonged photosensitivity; 40/42 did respond. Results: 38 patients showed photo-contact reaction, 1 photoaggravated reaction, and 3 contact allergic (CA) reaction to KP. Simultaneous photo-contact allergic reactions were frequently observed not only to structurally related but also to non-structurally related NSAIDs and sunscreens. Simultaneous CA to fragrance components was common. 1/3 of the patients reported prolonged photosensitivity, i.e. from 1 up to 14 years after having stopped KP application. Conclusions: The history is often not a good guidance to determine KP-related (photo) allergic contact dermatitis and the severe clinical symptoms sometimes require hospitalization, and/or systemic corticosteroids. As for the association between KP and sunscreen intolerance (being 1 of the possible causal factors for recurrent dermatitis), routine standard photopatch testing with KP might be indicated.