Help with a small rash on my armpit. Need an OTC cream or something to rid it?

Underarm rash. Underarm rashes may be the result of an allergic reaction to a deodorant or antiperspirant. However, heat, fungal skin conditions as well as razor burn may be to blame too. A rash under the arm can be embarrassing as the urge to scratch may be over powering. You can try otc cortisone twice a day but if not improved see your doctor.