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.