Light Brown Streak In The Left Hand Thumb Nail. What Could This Be?

Posted on Mon, 11 Nov 2013

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Mon, 11 Nov 2013 Answered on

Tue, 3 Dec 2013 Last reviewed on

Question : I have a light brown streak going down the length of my left hand thumb nail. I'm Caucasian and haven't experienced any trauma to my hand. Just happen to notice it in the past week so I can't really tell you how long it has been there. I feel like I would have noticed it previously, but who knows. It only appears on one nail.

Answered by Dr. Pavan Kumar Gupta (1 hour later)

Brief answer....it is called as melanonychia. Detailed answer... Hello, Thanks for the query. Melanonychia is actually the presence of melanin pigment in the nail plate. It generally presents as longitudinal band but can cover the entire nail or may present as transverse band also. Sometimes melanonychia can occur due to trauma,fungal infections,drugs like anti malarials and sometimes due to skin conditions like psoriasis or lichen planus. For proper diagnosis,you would have to consult a dermatologist ,who can perform a biopsy and get to the diagnosis. I hope it helps however you may revert to me for any further query. Best of luck Thanks

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar