Son has rash on chest, back, neck & right side of face. hasn't gone away for 24 hours and he has had benadryl. history of laundry soap giving a rash, but never lasted this long & benadryl made it go away?

Rashes can be caused by topical exposures as well as ingested exposures. Make a thorough evaluation of all chemicals that may have been used on anything coming in contact with these areas. It could be a pillowcase, cushion, clothing, towel, sheets, even your clothes, that have been exposed to a new allergen. Use childrens claritin for the next two weeks for non drowsy allergy control.