21 yo male presents with laceration over his distal 4th metacarpal. Initially the patient doesn’t recall how the injury occurred, but with additional probing you discover he was in an altercation last night and punched another person in the mouth. A x-ray shows no fracture and no retained foreign body. What do you do now?
Closed fist injuries in which lacerations occur over or near the PIP or MCP joint are at particularly high risk for infection through direct inoculation of the joint itself or through contact with the extensor tendon that then seeds the joint space.
Data from several studies in the 1980s of patients with closed fist injuries that went to the OR for surgical exploration found that 62-67% of the cases had joint involvement. More recent prospectively collected data by Shewring et. al. found that 96% of 147 patients with closed fist injuries over the PIP or MCP and taken to the OR for exploration had confirmed joint involvement.
Because of this, all patients with fight bite injuries need:
- Consult for wound exploration and OR for washout and debridement
- Antibiotics covering human oral flora (Streptococcus sp., Staphylococcus sp., Eikenella sp., and anaerobes):
- Unasyn (ampicillin/sulbactam) IV followed by Augmentin (amoxicillin+clavulanate) PO
- Third generation cephalosporin + flagyl or clindamycin IV followed by trimethoprim-sulfamethoxazole OR cefuroxime(2nd gen cephalosporin) PLUS clindamycin
Source:
Edens et. al. Mammalian Bites In The Emergency Department: Recommendations For Wound Closure, Antibiotics, And Postexposure Prophylaxis.Emerg Med Pract. 2016 Apr;18(4):1-20.
Larry Baddour. Soft Tissue Infections Due to Human Bites. In UpToDate. Sept 15, 2017.
Patzakis M, Wilkins J, Bassett R. Surgical findings in clenchedfist injuries. Clin Orthop Rel Res. 1987, 220: 237–40.
Shewring et. al. The management of the clrenched fist ‘fight bite’. J Hand Surg Eur Vol. 2015 Oct;40(8):819-24.
