Welcome to Healthcare Magic,
As per your given clinical details,there is more possibility that the cause of rash is due to painkiller allergy
. and the elevated liver enzymes
(mild elevations) are common in analgesic
usage or any minor insults to the liver. So i suggest you to keep record of the pill which has caused the allergy,next time keep him away from the same formula.
About final thing Bathing has no relation to the insulin