A 7-year-old boy was presented with abdominal pain for 3 days, and developed swelling and pain on both knee-joints and restriction of motion after taking cefaclor 0.25g 3 times. It was considered to be associated with drug allergy. The boy had a history of allergic responses to penicillin ,so cefaclor was discontinued. Physical examination showed a lot of petechial rash on both lower limbs with symmetric distribution. He was diagnosed as dermato-joint allergic purpura and given therapy with corticosteroid etc. 3 days later, his symptoms lessened and resolved gradually.
