Skin that becomes red and itchy after sun exposure is usually due to the occurrence of solar dermatitis, which should be treated as soon as possible by getting out of the light and with the use of topical medications. Solar dermatitis, also known as acute sunburn, is an inflammatory reaction that occurs when the skin is overexposed to ultraviolet light. Solar dermatitis is usually characterized by redness, swelling and pain of the skin, and in severe cases, even blisters, flaking, hyperpigmentation, etc. Patients with generalized solar dermatitis may experience general symptoms such as malaise, chills and fever. When the patient appears sunburn, should be immediately removed from the light source, and can use topical glycerine lotion, glucocorticoids such as hydrocortisone dihydrogenate cream and other drugs in the affected area for application. If necessary, you can take antihistamines such as loratadine under the guidance of a doctor to relieve the symptoms of skin allergies. You should pay attention to sun protection, wear sunscreen when you go out, and try to avoid sun damage to the skin. When solar dermatitis occurs, you should avoid scratching to avoid aggravation of the symptoms.