My son, 12 yes od, has a raised rash on his armpit and now a bit on his tummy, that has gotten progressively worse over the last couple of days. I have gone through the checklist of possible things we have done, or touched, but we really have done nothing diffrrent. Thoughts? We have put Cortisone and a Antifungal cream on it, which does help a bit. He also now has a stomach ache, could that be related??