Darkening of the skin under the arms can be a natural response to the irritation produced by moisture, certain deodorants, and constant shaving. Some people find that switching deodorants or stopping to use deodorants at all (if you do not have much body odor) can help. Additionally some find that using a regular exfoliating preparation can keep the skin softer, smoother, and prevent the thick buildup that causes darkening. Others find that switching from shaving to waxing will do the trick. This works by reducing the trauma to the skin caused by waxing, which is what thickens and darkens the skin. Occasionally darkening of the skin under the arms can be a sign of an underlying disorder, such as impaired processing of sugar which can be a sign of pre-diabetes. As always the diagnosis and the management of your particular skin concern will require a physical examination by your personal physician. Setting up a visit with your dermatologist
or your primary care doctor
might be advised.