Hello. Thank you for writing to us I suggest a possibility of Becker s nevus. It is an epidermal nevus or birthmark however it is later in onset. After puberty it often becomes darker and quite hairy, under the influence of hormones. The surface may also become raised and rough. Occasionally acne may develop in the nevus. There is no effective treatment for Becker nevus. The pigmentation can be reduced by a Q switched Nd:YAG Laser. Multiple sittings may be required. The laser is not always effective and pigmentation may return or even may be made worse by laser treatment The excessive hairs can be reduced with a Diode laser or by electrolysis. Most of the patients are quite happy to know that it is just a birth mark and accept the fact that no effective intervention is available. Regards