Hello,
Please elaborate on the symptoms and description of rash so that we can help you in a better way. Moreover steroids should be used under a dermatologist’s guidance as they are not without side effects and can cause skin thinning, atrophy skin and telangiectasia etc.
I hope it helps. Take care and regards.
Sice i CAN'T see the rash, and many rashes look alike, you are best going to your family MD and letting her/him take a look at the rash BEFORE you use the cortisone 10 on it.