Itchy neck after being exposed to the sun, consider solar dermatitis, polymorphic sun rash, cholinergic urticaria and so on. 1. Solar dermatitis: solar dermatitis is also called acute sunburn, mainly caused by prolonged exposure of the skin to ultraviolet radiation caused by a kind of inflammatory reaction, the main manifestation is to accept the sun for a few hours after the emergence of a clear border of bright red erythema, and blisters and other serious cases. 2. polymorphic solar rash: polymorphic solar rash is not particularly clear, generally and sunlight induced by the relationship between the majority of patients in the sun within a few hours after the sun will appear in the sun parts of the rash, generally accompanied by itching. 3. cholinergic urticaria: this is a kind of urticaria, mainly in the skin center temperature rise when the symptoms, appear small and especially itchy dot-like wind bumps. There may be other reasons for the itchy neck after being exposed to the sun, it is recommended to go to the hospital in time, complete the examination to clarify the cause of the disease, and then give targeted treatment or treatment.