Re: skin fungus?
Those are the area's where he will sweat or clothes will irritate. Especially in hot weather. It the foot section of the Pharmacy they sell powder made for foot fungus. He should put that on after showering, or try Gold Bond. Also in the Jock itch section they sell "Lotramin Spray" use that and keep the areas uncovered as much as possible. Once the rash goes away, continue to use powder treatment. Fungus can be funny, even though it appears to be gone it can still be there and will come back worse and become resistant to anti-fungal medications.