Our expert says:
Littlewing, it might be due to contact dermatitis or an allergy due to the deodorant, but it might also be due to something else like a superficial fungal infection. The best would be to let your doctor take a look and make sure it is nothing serious. In the meantime use as little as possible deodorant (maybe use some powder instead) and try to get some sunlight on the area. Good luck.
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal
advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.