Once the sun is itchy skin, consider solar dermatitis, lupus erythematosus, polymorphic solar rash.
1. Solar dermatitis: after sun exposure, the proteins and nucleic acids in the cells absorb a large amount of ultraviolet light, which will produce some complex photobiochemical reactions, causing vasodilatation, tissue edema, melanin synthesis, etc., resulting in itchy skin symptoms.
2. Lupus erythematosus: this is a diffuse connective tissue disease, will involve the whole body multiple systems, in the skin there will be a rash, in the sun will appear erythema caused by itching.
3. polymorphic solar rash: polymorphic solar rash is not clear, may be sunlight-induced delayed hypersensitivity mediated, the cause of the disease may be genetically endocrine and metabolic abnormalities related to the manifestation of a sunburn itchy skin symptoms.
A sunburn itchy skin may also have other reasons, it is recommended to consult a doctor in time, under the guidance of the doctor for the cause of the selection of appropriate medication, usually do a good job of sunscreen, try not to go out in the ultraviolet light strong time.