The crevices are the underarms. Underarm blackness is mainly caused by excessive production of melanin in the armpit, accumulation of formation or post-inflammatory deposition of color, which can be removed by laser treatment and medication. 1. Laser treatment: Through the physical means of laser, using strong pulse, under the action of which, penetrate the skin surface layer, the melanin particles of the skin will be broken, and then through the body metabolism out of the body, you can improve and remove the situation of underarm darkness. 2. Drug treatment: underarm black is mainly too much melanin, so you can follow the doctor’s instructions to use Vitamin A cream, hydroquinone cream, arbutin and other drugs for treatment, these drugs have to promote melanin discharge and inhibit the role of melanin synthesis, you can improve and remove the underarm black. Underarm black if you need to be treated, need to be under the guidance of a physician, not self-medication, to avoid adverse consequences.