Fight Bite: Diagnosis and Management in the ED

Fight bite or “clenched fist” injuries are notoriously easy to miss. They are often subtle (3-5 cm) appearing lacerations over the dorsal metacarpophalangeal (MCP) joint that occur as a result of the hand striking teeth. Oftentimes, the patient may be intoxicated or withhold history, so a high index of suspicion and a thorough exam are essential. Patients may also view the injury as benign until more serious complications occur.

The location of the injury is susceptible to infection as the skin offers little protection over the important structures underneath. Often, after making contact, the hand is extended and oral bacteria are pulled further into the wound. This can result in a serious infection of the joint space, deep soft tissue, and tendon sheaths. Combined with delayed presentation and delayed diagnosis, fight bites have the highest incidence of complications of any type of bite wound.¹ One study documented that full rehabilitation of normal hand function after MCP joint pyogenic arthritis was achieved in only 10% of patients.²

If the patient presents late with a clinically infected hand, disposition is straightforward as the patient must be admitted for wound exploration and washout in the operating room. Antibiotics may be started prior to surgery or after surgical wound cultures depending on the recommendation of the hand surgeon.

For patients who present earlier with non-infected closed hand injuries, management is less straightforward. Some practitioners recommend admission, washout, and IV antibiotics for all human bites to the hand.

A more selective approach relies on careful examination of the wound. An x-ray is obtained to evaluate for foreign bodies and fractures. A thorough exam should be performed on the hand throughout its entire range of motion, focusing on possible joint, tendon, or deep space injury. A copious amount of irrigation and debridement are standard, and splinting of the hand in functional position is recommended. Tetanus status should be assessed and pain control provided. Prophylactic antibiotics such as amoxacillin/clavulanic acid are recommended. If there is no evidence of infection or joint or tendon violation, the patient may be discharged with prompt follow-up with hand surgery and return precautions.

Sources:

Bunzli W., Wright D.,Hoang A., et al. Current management of human bites.Pharmacotherapy, 18 (1998), pp. 227–234¹

Chadev,A., Jukhtin, V Butkevich, A., et al.Treatment of infected clench-fist human bite wounds in the area of metacarpophalangeal joints. J Hand Surg Am, 21 (1996), pp. 299–303.²

Perron A., Miller M. And W. Brady. Orthopedic pitfalls in the ED: Fight Bite. AJEM. March 2002. Vol. 2.2.114-117