5Dark Lines On the Toenails or Fingernails
The appearance of a black or dark area under your toenail or fingernail which shows up without a clear injury must always be checked. In many cases, it is a common symptom of subungual melanoma or melanoma in the nail bed. This condition usually occurs when a pigmented streak of your nails involves the Hutchinson’s sign or cuticle. These signs are most common on the big toe and thumb but may also happen on any nails. While subungual melanoma is not so common in whites, which only accounts for approximately 1% of melanomas, it is the most common type of melanoma that is found in dark-skinned people. [5]
