Your underarm is one of the most sensitive parts of your body and is extra prone to sensitivity reactions. Often when switching from commercial antiperspirants or deodorants to "all-natural" deodorant our underarms experience a "detox" period. So, don't throw away your ManSpray just yet, it's actually good for you.The best course of action is to refrain from using anything in your underarms for about 7 days and continue to wash thoroughly. This will allow your body to "detox" some of the bad elements which are causing the rash. After 7 days, you can continue to use and enjoy the benefits ManSpray has to offer.