What causes dark line in thumbnail?

What causes dark line in thumbnail?

Melanonychia is caused when the pigment cells, called melanocytes, deposit melanin into the nail. Melanin is a brown colored pigment. These deposits are usually grouped together. As your nail grows, it causes the stripe of brown or black to appear on your nail.

Why do I have dark streaks under my nails?

“Splinters or dark streaks under nails can occur when microscopic areas of bleeding happen and allow blood to settle under the nail,” says Dr. Joel Schlessinger, MD, board certified dermatologist and cosmetic surgeon with a private practice in Omaha, NE. “This also occurs in psoriasis where nail deformities are common,” he continues.

What causes a black line on the bottom of the nail?

A malignant tumor in a nail nearly always affects just one nail. Dark lines on several nails that all look the same are very likely benign. Dr. Schlessinger adds, “The colors can be anything due to nail thickness and different areas where moles can originate.

Why do I have a black line on my finger?

“This also occurs in psoriasis where nail deformities are common,” he continues. “A dark streak or area of the nail with dark discoloration can be a sign of melanoma and should be evaluated if there is no reason that trauma could have caused it.

What does a melanoma streak look like on a finger?

They also tend to be comprised of varying shades of brown to black, or if just brown, the shades usually still vary. Melanoma streaks may also be tan, grey or dull pink. Melanoma streaks may be thick enough to look more like bands than lines.

What causes a dark line under the nail?

“A dark streak or area of the nail with dark discoloration can be a sign of melanoma and should be evaluated if there is no reason that trauma could have caused it. “The dark streak from melanoma is due to actual cells being grown in the nail area or under the nail.”.

What does it mean when you have black streaks on your fingernails?

The black or brown band is wider across than three millimeters. The appearance of the pigment band has changed. The thumb is most commonly affected, followed by the big toe and index finger. Hutchinson sign or the discoloration extends into the nail fold or cuticle.

They also tend to be comprised of varying shades of brown to black, or if just brown, the shades usually still vary. Melanoma streaks may also be tan, grey or dull pink. Melanoma streaks may be thick enough to look more like bands than lines.

“This also occurs in psoriasis where nail deformities are common,” he continues. “A dark streak or area of the nail with dark discoloration can be a sign of melanoma and should be evaluated if there is no reason that trauma could have caused it.