Small itchy red bumps on the body are considered to be urticaria, which is a metaplastic disease caused by the dilation and increased permeability of small blood vessels after the skin mucosa is exposed to allergic substances, usually subsiding within 2-24 hours, but repeatedly occurring new rashes, most of the allergic substances are mites, dust, animal hair, flowers and plants, etc. If the local area is relatively small, you can use local anti-itch and anti-swelling drugs, such as furnace glycolic lotion. If the symptoms are relatively large, you can take oral antihistamine treatment, such as loratadine tablets and cetirizine tablets, and the symptoms will basically subside after 3-5 days of treatment. In general, you should pay attention not to eat allergy-prone foods, such as seafood, mangoes, durian, etc., and avoid contact with environmental pollutants.