Betamethasone dipropionate prescribed for contact dermatitis under breast (folds)-is it safe to use, how to know redness wont be back after stop using?

Contact dermatitis: Normally betamethasone diproprionate should not be used under the breast folds. It is too strong for the thin skin in this area and prolonged use will cause atrophy. That said if it is truly severe contact dermatitis ( like poison ivy) 2 or 3 days use would be ok. I wouldn't use it if only redness. How was the diagnosis established? Better to use a weaker steroid