Subungual Haematoma vs Melanoma

A subungual haematoma often follows a knock, tight footwear or repeated pressure. The colour may be red, purple, brown or black, and the mark should gradually move towards the nail edge as the nail grows. Melanoma under a nail may appear as a brown or black longitudinal band, especially when colour is uneven, becomes wider, or extends onto the surrounding skin. It can occur without a remembered injury. A dark mark can have other benign causes too, so appearance alone cannot confirm or exclude cancer.

Take a clear photograph with the date and note any injury, new footwear, pain or change in width. Do not drill, cut deeply or try to drain the nail yourself. Arrange a dermatology assessment for a mark without a clear cause, one that does not grow out, or pigment affecting one nail in a changing pattern. If melanoma is suspected, the clinician may recommend examination and sometimes a biopsy or surgical excision to establish the diagnosis.

Seek prompt review for a new or changing dark band, irregular colour, pigment on the skin beside the nail, nail splitting, persistent bleeding, a lump, or a mark that is not moving with nail growth. Urgent care is appropriate for severe pain, spreading redness, pus or fever after an injury. A possible melanoma should not be dismissed because it is painless or because trauma is suspected.

Does this mark appear to be growing out with the nail? Is dermoscopy or a biopsy needed? Could trauma or medication explain the colour? If melanoma is confirmed, what staging tests and treatment options apply?