“Dogs never bite me. Just humans.” -Marilyn Monroe
Human bites are the third most common bite after dog and cat bites. They occur more frequently in males, typically between the late teens and in the twenties. Closed fist bites are typically caused by punching another individual in the mouth. The dorsal aspects of the 3rd and 4th MCP are most commonly affected. Bacterial flora from the mouth can enter the joint space. Once the fist is relaxed and the hand opens, the bacteria can become trapped in the joint space. The most common affecting organisms are Streptococcus, Staphylococcus, and Eikenella.
Patients may present with pain, swelling, and erythema at the site. A complete hand exam is necessary, with specific focus towards concern for extensor tendon laceration. The wound should be copiously irrigated and cleansed. An X-ray should be done in most cases to rule out retained tooth fragment, foreign bodies, and fracture. In general, wounds should be left open.
Antibiotic coverage should cover Streptococcus, Staphylococcus, and Eikenella. Ampicillin/sulbactam or Amoxicillin/clavulanate should be considered. Avoid antibiotics that do not have coverage against Eikenella (e.g., first generation cephalosporins such as cephalexin, pencillinase resistant penicillins such as dicloxacillin, macrolides such as erythromycin, clindamycin, and aminoglycosides). Clindamycin can be considered as an adjunct for better anaerobic coverage.
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Image courtesy of AMP EM (osuemed.wordpress.com).