Chaffing armpits

My husband calls that crate rot! lol My dogs get it on the inside of the rear legs or arms sometimes. Make sure it is not allergies I know Typhoon gets it from time to time and it is allergies. Bag balm works good or even a triple antibiotic cream is ok. When that happens I just leave it alone and it goes away in a few days but if it stays or happens alot again it could be allergies.