Abstract
A 48-year-old woman developed photocontact dermatitis on her forearm due to sunscreen. The previous summer she had developed photocontact dermatitis on the dorsal side of her left foot after using a plaster containing ketoprofen. We subjected the sunscreen and the ingredients of the ketoprofen-containing plaster to patch and photopatch testing.
The photopatch test produced a positive result for ketoprofen, and both the patch and photopatch tests produced positive reactions to the ultraviolet A absorbent avobenzone, which was present in both the sunscreen and plaster.
We surmised that the patient’s most recent episode of photocontact dermatitis had been caused by the avobenzone in the sunscreen and advised the patient to avoid this substance. Thus, patients with a history of photocontact dermatitis caused by a ketoprofen-containing plaster should undergo patch and photopatch testing of all of the ingredients in such plasters and should be advised of the implications of any reactions they display to components that are used as ultraviolet absorbers.
