Skin itchy in the sun may be caused by photosensitive dermatitis, solar dermatitis and other causes. 1. photosensitive dermatitis: photosensitive dermatitis is affected by photosensitive substances or photosensitizers, skin lesions caused by sunlight exposure, manifested as a diffuse bright red skin surface rash, blisters, vesicles, flaking, swelling and other symptoms, accompanied by an obvious burning sensation, itching or tingling sensation. 2. Solar dermatitis: solar dermatitis is due to excessive exposure of the skin to ultraviolet radiation produced by the inflammatory reaction, usually a few hours after sun exposure to more than ten hours, the main manifestation of the skin surface appeared in a clear boundary of the erythema, the serious blisters can be ruptured, vesicles, etc., and some patients may be accompanied by a burning sensation, itching sensation. Skin itchy in the sun, there may be other causes, it is recommended to go to the hospital in time to improve the examination, to clarify the cause of the disease to give targeted treatment.