The arm acne phenomenon, consider and eczema, folliculitis, keratosis pilaris and other factors, according to the different diseases to choose the appropriate drug treatment. 1. Eczema: small acne on the arm phenomenon, may be due to eczema factors, usually accompanied by local itching symptoms, after diagnosis can cooperate with the doctor to choose hydrocortisone, dexamethasone and other glucocorticosteroid medication, to play the effect of anti-itch and anti-inflammatory. 2. Folliculitis: this is a skin disease mainly involving hair follicles, manifested as red papules on the arm follicles, accompanied by itchy symptoms, and Staphylococcus aureus infections, can cooperate with the doctor to choose fusidic acid, mupirocin and other anti-infective ointment treatment. 3. Perifollicular keratosis: it occurs on the upper arms and thighs, symmetrically distributed, occasionally generalized distribution. Involved parts of the skin have special roughness, lesions for the needle tip to millet grain size follicular papules, skin color, not fusion. Topical topical retinoic acid ointment, salicylic acid ointment, urea cream, etc. can be used to soften or dissolve keratin and improve symptoms. Arm long small acne may also have other reasons, can cooperate with the doctor first clear cause, and then do targeted treatment, do not blindly use drugs.