Redness, swelling and hard lumps after taking DPT vaccine may be caused by vaccination reaction, infection or allergy, which can be treated by daily care, local medication and systemic medication. 1. Daily care: If there are redness, swelling and hard lumps on the day of DPT vaccination, you can apply ice packs first, and then apply hot packs after 48 hours, which can accelerate blood circulation and help reduce swelling. 2. Local medication: If the redness, swelling and hardness are caused by local infection and inflammation, you can apply erythromycin ointment or mupirocin ointment. The use of drugs need to follow the doctor’s instructions. 3. Systemic medication: for the redness, swelling and hard lumps caused by infection and inflammation, you can take cefixime and cefaclor orally; for the redness and swelling caused by allergic reaction, you can take cetirizine and loratadine for anti-allergy treatment. The medication should be taken according to the doctor’s prescription, not self-medication. After the DPT vaccine local redness, swelling, hard lumps, you need to understand the cause and then targeted treatment, specific should follow the doctor’s instructions.