A 50-year-old white woman presents with subungual and acral pigmentation of the left middle finger. She first noticed a black streak down the middle of her nail 10 years prior to presentation. Subsequently, the pigmented band on the nail plate widened and darkened, with pigment spreading to the proximal nail fold and distal acral hyponychial skin. She has no associated symptoms, including nail splitting, bleeding, or pain, and no history of acute or recurrent trauma. Several years previously, she was reassured that her nail pigmentation was benign. The nail examination is illustrated in the Figure. Examination of all other nails is unremarkable. Past medical history and family history are unrevealing.
Fox GN. Chronic Nail Pigmentation in a 50-Year-Old Woman. JAMA. 2014;311(13):1350-1351. doi:10.1001/jama.2013.286235