Allergic contact dermatitis from sunscreen preparations complicating photodermatitis.

Two men with known histories of photosensitivity had apparent exacerbations of their dermatoses. Patch-testing showed the presence of allergic contact sensitivity to the sunscreens that they were using. The clinical distribution patterns of adverse reactions to sunscreens naturally simulate sun-induced reactions, thus providing clinical problems that require evaluation by both patch and photo-patch tests. These findings emphasize that allergic contact or photo-contact dermatitis from sunscreens that are used for prophylaxis of photodermatitis can actually complicate or aggravate the preexisting state of photodermatitis for which the sunscreens are prescribed.