A rash called erythema multiforme? My son has it right now. He actually had it a couple of weeks ago so I took him to the dr and was told to just give him benadryl. The rash went away in like 5 days but now it is back again. It doesn't hurt him he just has these spots all over his little body. I'm just confused by what may be causing it as I took to dr. google and it says there is no exact cause for the rash.