Itchy arms with a lot of small bumps, you need to decide the treatment measures according to the cause of the disease, the common causes are eczema, contact dermatitis, infection and other reasons. 1. Eczema: internal and external stimulation of a variety of factors caused by the skin inflammatory reaction, will cause the disease arm with a lot of small bumps very itchy, can be used externally with glycerine lotion, zinc oxide ointment and other drugs. At the same time can be combined with oral antihistamine drugs such as loratadine. 2. Contact dermatitis: Inflammatory reaction that occurs when the arms are exposed to certain sensitizing or irritating substances. At this time, it is necessary to clarify the causative factors and avoid, at the same time, topical glucocorticoids such as mometasone furoate, oral antihistamines such as cetirizine and other drugs. 3. Infection: fungal infection caused by Malassezia folliculitis, can be used externally clotrimazole ointment, ketoconazole ointment and other antifungal drugs; viral infection caused by herpes, early can be used externally glycerine lotion, acyclovir ointment and other drugs. The arm has a lot of small bumps very itchy, there may be other reasons, it is recommended to go to the hospital in time to clarify the cause of the disease, and follow the doctor’s instructions for treatment. The drugs mentioned above should be used according to the doctor’s advice.