Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
There are five categories of injury that can occur to the nail. Often, a combination of these injuries occurs in the same nail.
A subungual hematoma (nail bruise) is a
collection of blood under the nail. It is usually a red or purple color, which
fades to blue over a few weeks. The entire finger or toe throbs with every
heartbeat and is painful to touch or even move through the air. A nail bruise
may occur by itself, or it can be seen in combination with other nail injuries.
A nail laceration can refer to a cut through the nail, to the nail bed, to the cuticle or lateral nail folds, or any combination of these. There is always blood visible on the skin. The nail can appear quite mangled depending on the type of injury.
A fingertip amputation means that a portion of the fingertip, including part or all of the nail, has been removed from the rest of the finger. Bone may or may not be visible.
A nail avulsion occurs when a portion of the nail is lifted off the nail bed or is sticking out of the skin at the base of the nail (the cuticle). There is usually blood visible. This is often associated with a laceration.
A fracture of the bone under the nail can also be associated with injuries to the nail, particularly with crushing injuries. This is called a distal tuft fracture. Unless there is an obvious bend (deformity) in the end of the finger, an x-ray will be needed to make this diagnosis.