How To Cure Raised,swollen Skin Patches On Both Arms And Elbow?

14 month old boy awoke with raised, swollen skin patches on both arms at back of elbow. The raised skin is almost identical on both elbows, he has a fever of 102.3, and his ears are red. He has a history of eczema and I have been treating cortisone 10 cream when needed. He has not had any vaccines yet. He is healthy & average height and weight and has no known food allergies. Should I wait to see if these swollen skin patches clear up on their own? What may cause a rash in this area?