Most arm itching without a rash is due to dry skin from sun exposure. If accompanied by a rash, it may be caused by contact dermatitis, eczema or solar dermatitis. 1. Dry skin due to sun exposure can lead to arm skin itching, you can generally use warm water to wash it can be relieved, in the sun it is best to wear sunscreen clothing, apply some sunscreen cream and so on to prevent. 2. Contact dermatitis can be treated by staying away from allergens, using topical hormones such as mometasone furoate, dexamethasone, etc. or oral antihistamines such as chlortetracycline, etc., and secondary bacterial infections can be treated with antibiotics. 3. Eczema, in the acute stage, when there are no blisters, vesicles, oozing, you can use glycerin lotion or glucocorticoid ointment. A large number of oozing should be used cold wet compresses, commonly used 3% boric acid solution; chronic can be used externally glucocorticosteroid ointment or exfoliators such as salicylic acid ointment. 4. Solar dermatitis, generally avoid sun exposure, local aloe vera gel, moisturizing cream can be applied. You can also use glycerite lotion, non-steroidal anti-inflammatory drugs, antihistamines such as chlorpheniramine maleate tablets under medical supervision. There may be other causes of arm itching, it is recommended to go to the hospital in time, to clarify the cause of the disease, symptomatic treatment.