Don't worry...you are suffering from acanthosis nigricans causing this darkness.. Specific medicine available for good control... Treatment depends on the severity..Do direct online consultation for detailed prescription by sending photos.

Dark underarms usually aren't a sign of anything serious, but some may find them embarrassing. Darkening is often due to a skin condition called acanthosis nigricans or it could b waxing associated or even post a allergic reaction. Sometimes there can b normal hyperpigmentation of certain areas of ur body like underarms and groin areas. Your skin colour is determined by pigment cells called melanocytes. When these cells multiply more, they can turn the skin a darker colour. It can b controlled with creams or lasers. Surgery isnt required. Consult a Dermatologist for the same.