Itching suggests allergic disease, consider the possibility of acute urticaria or allergic dermatitis, it is recommended to take oral anti-allergy medication and topical application of medium to weak glucocorticoid cream can be used, such as cetirizine tablets and trimethoprim econazole cream. Itching is the most common manifestation of allergic diseases and includes many possibilities. If the red bumps can subside naturally without leaving traces and then occur elsewhere, suggesting acute urticaria, oral anti-allergic drug treatment needs to be emphasized, choosing 1-2 of loratadine, imipramine and cetirizine, and using them regularly every day, insisting on 1-2 weeks until 5-7 days after the rash is controlled. If the rash does not subside on its own and persists, consider generalized atopic dermatitis. Most of this systemic allergy is caused by food. Carefully recall your diet for 3 days before the onset of the disease, or any experience with sun exposure or use of specific medications. Treatment places more emphasis on topical medication than on urticaria, 2-3 times a day, with minimal scratching. If there are recurrent attacks, serum allergen screening or patch test can be perfected to find allergens. Allergic diseases during treatment, are noted to drink more water to help allergens metabolism discharge, more rest to ensure recovery, do not drink alcohol, do not eat new food, especially seafood beef and mutton and other irritating food, less scratching, do not scald the skin.