Hello doctor, I am a 26-year-old male. I have black/brown patches on my back below the neck. The whole of my upper back portion has turned black/brown. It has been around 10 years this discoloration started but is now constant (not spreading) for the past 4-5 years.
Hi. It is pigmented hairy epidermal nevus (Becker nevus or Beckers melanosis). The first appearance of this nevus is in adolescence. It presents as an irregular, hyperpigmented patch. Once present these nevi stabilize after several months or years. Becker nevus is a benign condition and malignant transformation is rare. No treatment is required, although lasers have been used for cosmetic benefits. Its cause is familial and occurs due to mutation. Genetic counseling should be tried.