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Ask A Skin Doctor: Subungal Melanoma ABCDEF

Dear Doctor

After wearing my new shoes which was tight for my legs, especially the right one. After that a dark streak appeared on my right big toenail.

After than I again used it and my third and fifth nails also turning black at the right edge.

Then I read about melanoma and other nail disease and scared of it. Even after giving up the tight shoes for about a month, still the discoloration exists as such.

Why? I am totally upset. The big toenail color seems sometimes darkened and sometimes lightened.

subungal melanoma ABCDEF

Dear Patient

The subungal melanoma ABCDEF guidelines are as follows:

A Age since peak incidence is from the 5th to the 7th decade and it mostly affects African Americans, Asians and native Americans

I do not know your age or race

B Brown to black in color and with a width of 3mm or more with variegated borders

The color of your bands is blackish and you would need to measure their width at home.

C Change in the nail band or lack of change despite adequate treatment

I do not know whether the nail band has changed or not if it was being treated for another condition as is the case in some situations.

D Digit most commonly involved which is the thumb or hallux

The large toe (hallux) is affected

E Extension of pigment onto the proximal and/or lateral nailfold (Hutchinson’s sign)

This is evident in the large toe

F Family or personal history of dysplastic nevus or melanoma

I do not know you family history.


Therefore, I suggest that you go to your nearest dermatologist because the dark color extends to the skin on the large toe.

The dark lines or melanonychia in the third and fifth toes are not worrying because they do not extend to the flesh of the toe. They can be explained by friction from your tight shoes causing melanocytic activation.

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Categorised as: Ask a Dermatologist Online | Nail Diseases

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