A few red raised bags on the arm is very itchy may be related to papular urticaria, acute eczema and other factors, the patient needs to be based on the specific cause of the application of drugs to deal with, such as antihistamines, glucocorticoid drugs and so on. 1. papular urticaria: papular urticaria is often manifested as the appearance of clustered or scattered red, windy, doughnut-like damage, accompanied by varying degrees of itching. When it occurs on the arm, the patient can appear on the arm with a few red raised bags very itchy, usually need to apply antihistamines for treatment, such as benzylamine hydrochloride tablets, chlorpheniramine maleate tablets and so on. 2. Acute eczema: Acute eczema in the early stages of the manifestation of erythema and accompanied by a burning sensation and itching, and then in the erythema will appear pimples or small blisters, usually can be used externally with glucocorticoid drugs for treatment, such as hydrocortisone butyrate cream, compound dexamethasone acetate cream. There are other causes for the itchy red bumps on the arms (e.g. folliculitis), and it is recommended that the patient go to the hospital in time to find out the cause of the disease and then carry out standardized treatment to avoid delaying the condition.