Hi. My 8 year old son had a patch of ringworm on his leg several months ago that we attempted to treat with a prescription med from his pediatrician. It appeared to get better and all of a sudden he developed a fast spreading raised blotchy rash on his legs and elbows. It spread quickly to the entire length of his leg. Went back to the doctor said it was the medicine he was on. Two days later, it was worse. Doctor said it was an id reaction. Got better but the mottled color never went away on the back of his legs. Now the rash is coming back. What could this be?