[Melanonychia].

Melanonychia is seen, when melanin is incorporated in the nail, which gives a band of dark discolouration of the nail. Nail discolouration is a common cause for patients to seek medical attention, and it is often benign. Melanonychia can be seen due to melanocytic proliferation (ungual naevi), benign hyperplasia (lentigo) and hypermelanosis (infections, traumas). However, subungual melanoma also commonly presents with melanonychia and is often overseen, leading to a worse prognosis. It is therefore important systematically to examine all nail discolourations to find the cause and rule out malignancy.