Suggest Treatment For Itchy Bumps On Earlobes

My son has an itchy red rash on his earlobes. It's been here for 2 weeks. 3 weeks ago, he had rash on lower right leg. Looked like poison ivy. Doctor said contact dermatitis, given hydrocortisone 2.5% 2x a day with Bactroban ointment. A week later, rash spread to all extremities including earlobes. Went back, given prednisone 6.5 ml 2x a day for 5 days. The rashes on extremities are drying up but his ears are still red with some small bumps, very itchy. Hydrocortisone does not seem to work. Also giving him Benadryl. Also, same itchy bumps are also seen on his cheek.