Cosmetic photosensitive dermatitis is an inflammatory dry skin stirring caused by the use of cosmetics and then by light exposure, which is a phototoxic reaction or photo-allergic reaction of the skin mucosa caused by the photosensitive substances in cosmetics. Diagnostic criteria: 1, there is a clear history of cosmetic exposure and light exposure history. 2. The lesions mainly occur in the photoreactive areas after the use of cosmetics. 3. The lesions may appear in various forms, such as erythema, papules, small blisters, and itching; chronic lesions may show infiltration, thickening, mossiness, etc.; when they occur in the mucous membrane of the mouth and lips, they may show swelling, dryness, exudation, etc., and the onset of the lower lip is more common or heavier. 4.The course of the disease can be delayed, and the rash can still occur after stopping the use of cosmetics, and can develop again after being exposed to allergenic substances. 5. Positive cosmetic light spot patch test. 6. Exclude non-cosmetic-induced photosensitive dermatitis. Treatment principles: 1. Timely removal of cosmetics remaining on the skin. 2.Stop using the allergenic cosmetics and avoid light exposure. 3, according to the condition, according to the symptomatic treatment of photosensitive dermatitis.