Acne on the arms may be related to contact dermatitis, perifollicular keratosis, folliculitis and other factors. Usually, general treatment and medication can be used. 1. Contact dermatitis: when the skin of the arm is stimulated by external substances, it will cause inflammation of the skin of the arm, which will be manifested as the phenomenon of arm acne. Usually, you can follow the doctor’s instructions for drug treatment, such as arm area coated with glycerine lotion, or external glucocorticoid cream such as hydrocortisone butyrate cream, compound dexamethasone cream, etc., and avoid contact with allergenic substances during the treatment period. 2. Keratosis pilaris: caused by abnormal keratinization of the epidermis of the hair follicle, usually related to genetics, metabolic disorders, etc., can also cause symptoms of arm acne. You can use urea ointment or salicylic acid ointment as prescribed by the doctor to promote keratolysis and improve the symptoms, and you can also use moisturizing cream to avoid dry skin and improve the discomfort. 3. Folliculitis: If the arm skin follicles are damaged secondary bacterial infection, thus causing an inflammatory reaction of the hair follicles, will also trigger arm acne. You can use povidone-iodine to apply sterilization, and if the inflammation is obvious, you can follow the doctor’s instructions to use clindamycin gel or mupirocin ointment for anti-inflammatory and sterilization, and usually pay attention to the cleanliness of the arm skin. If you have arm acne, it is recommended that you go to the hospital in time to find out the cause of the disease and then targeted treatment. The above drugs should be used in accordance with medical advice.