Reverse bite injury

A reverse bite injury (also called a clenched fist injury, closed fist injury, or fight bite) results when, a person punches another person in the face, and the skin (and sometimes tendons) of their knuckles are cut against the teeth of the person they are punching. The proximity of the wound is often located over the metacarpophalangeal joint resulting in tendon injury.

The medical treatment of this injury is similar to those of a human bite, but may also involve damage of the underlying tendons. The potential for infection and other complications increases with late presentation. Management may involve cutting away infected tissue, which may include tendons and therefore involve loss of use of the hand; infection also tends to spread along the tendon sheath, so that what was originally a small injury goes on to involve the entire hand.

These injuries should be managed as other human bites: wound irrigation and antibiotics are essential as human saliva can contain a number of bacteria. If tendons or bone are visible through the wound, the urgent referral to a specialist hand surgeon is mandatory, even if no visible damage to the tendons is noted. Unfortunately, the nature of these injuries is such that even if the injury is optimally managed, catastrophic outcomes (loss of use of the hand, or loss of the hand) are not unusual.

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