Photoallergic contact dermatitis to musk ambrette. Clinical report of two patients with persistent light reactor patterns.

Two male patients with photoallergic contact dermatitis to musk ambrette, 2-methoxy-3,5-dinitro-4-methyl-t-butylbenzene, are reported. Musk ambrette is a synthetic fragrance material commonly used in foods and cosmetics. The clinical distribution of lesions presented by these patients strongly suggested an adverse reaction to light. Over a period of several years no etiology had been determined in these cases despite extensive testing and hospitalization. Photopatch tests to musk ambrette were positive. No other etiology for photosensitivity was found. This report emphasizes that exposure to household or cosmetic products represents a potential source of contact photosensitivity. Patients presenting with dermatoses of unknown origin confined to the light-exposed areas should have fragrances considered as possible etiologic agents.