Melanonychia is a medical term that refers to a condition characterized by the presence of dark pigment or discoloration in the nail plate. It is derived from the Greek word "melas," meaning black, and "onyx," meaning nail.
Melanonychia can manifest as longitudinal dark bands or streaks along the length of the nail plate. These dark lines may appear brown, black, or occasionally gray in color. The condition can affect one or multiple nails, and it commonly occurs in both fingernails and toenails.
There are two main types of melanonychia: longitudinal melanonychia and transverse melanonychia. Longitudinal melanonychia refers to the presence of dark streaks running from the base (cuticle) to the tip of the nail. Transverse melanonychia, on the other hand, involves dark bands that cut across the nail horizontally.
Melanonychia can have various underlying causes, including dermatological conditions, genetic predisposition, trauma to the nail, certain medications, systemic illnesses, or malignancies such as melanoma. It is important to differentiate between benign causes and potential malignant causes, as longitudinal melanonychia can sometimes be an early sign of melanoma, a type of skin cancer.
If an individual notices any changes in their nails, such as the sudden appearance or enlargement of dark streaks, it is advisable to seek medical attention for proper diagnosis and management.
