What could be the reason for the lines on my two fingers that did not grow out?

Hello,

Welcome to icliniq.com.

I read your query and understand your concern. It might be longitudinal melanonychia, a benign condition, and there is no need for treatment. But, on the other hand, it can be due to some physiological conditions and trauma. In most cases, they are self-limiting conditions and benign, so no biopsy is required. However, a biopsy is required only in cases where it is becoming extremely dark or if a mass is forming below it. Kindly revert for further queries. Thank you.

Hi,

Welcome back to icliniq.com.

In most cases, they are self-limiting conditions and benign. So, a biopsy is required only in cases where it is becoming extremely dark, or a mass is forming below it, and there are changes in the structure of the nail plate. Thank you.