Swollen arms after the DPT vaccine can continue to observe, you can also use medication to deal with the local treatment, serious to go to the hospital for treatment. DPT vaccine, after the vaccine itself is very easy to appear after the vaccine injection site of the local hard knot, is a normal phenomenon, but generally will slowly ease, so do not need special treatment. If the swelling of the arm is more serious or accompanied by pain, itching, you can apply local glycerine, hydrocortisone butyrate, or use warm water, hot compresses, potato slices, and so on. If the redness, swelling, heat and pain of the arm is more serious, you need to consider the combination of infection, and if there are pimples and rashes, you need to consider allergy. Symptoms are more obvious should go to the hospital, under the guidance of the doctor need to use amoxicillin, cefaclor and other anti-infections or the use of loratadine, cetirizine and other anti-allergy treatment. Specifically should be used under the guidance of a doctor.