When you look at your fingers or toes, do you see a brown or black discoloration on your nails? Those dark streaks are called melanonychia, and they can range from harmless to potentially deadly.
Dr. Michael Kim, a board-certified plastic surgeon, joined Gulf Coast News to discuss the dark streaks under your nails.
Melanonychia is brown or black pigmentation of the nail unit. It is more prevalent in people with skin of color. However, complications depend on the cause of melanonychia. Melanonychia, or brown/black nail discoloration, can be a sign of subungual melanoma. Often, it can be benign, requiring careful evaluation to distinguish between the two.
Subungual melanoma is rare. It is most diagnosed between the age of 40 and 70. It is not thought to be due to sun exposure. Trauma may also be a factor, accounting for the greater incidence in the great toe and thumb.
Dr. Kim says a good diagnostic approach to melanonychia is using the ABCDEF.
A) Age : the peak incidence in the fifth to seventh decade of life. Additionally, subungual melanoma accounts for one-third of melanoma cases in Asians, African Americans and Native Americans.
B) Brown-black band with a breadth greater than 3mm with variegated borders
C) Change in nail band morphology despite treatment
D) Digit involved: the thumb is more likely to be affected by subungual melanoma than the great toe; the great toe is more likely than the index finger to be affected by subungual melanoma
E) Extension of the brown-black pigment of the nail bed, nail matrix, and/or nail plate onto the adjacent cuticle and proximal and/or lateral nail fold (Hutchinson sign)
F) Family or personal history of dysplastic nevus or melanoma
For more information, reach out to Kim online .
WATCH THE FULL INTERVIEW.