Prolonged photosensitivity following contact photoallergy to ketoprofen

We report the third case of prolonged photosensitivity secondary to contact photoallergy to topical ketoprofen, a 2-arylpropionic acid derivative. The patient suffered from persistent photosensitivity for more than 1 year after the withdrawal of ketoprofen with recurrent eruptions on sun-exposed skin areas. This photosensitivity was associated with a persistent decrease in polychromatic and UVA minimal erythemal doses. Photobiological testing revealed cross-reactivity with fenofibrate and benzophenones. Photoallergy to ketoprofen is due to the benzophenone structure or to the very similar thiophene phenylketone of tiaprofenic acid, but not to the arylpropionic function. Thus, fenofibrate, tiaprofenic acid and benzophenones should be avoided by patients with a positive history of photocontact dermatitis to ketoprofen.