Closed fist infection

Background

• Also known as a "Fight Bite" or "Reverse Bite Injury"
• Result of striking another individual's teeth with clenched fist
• Although may appear benign, significant morbidity can result from late presentation or inadequate initial management
• Complications are frequent and include joint violation (68%), tendon injury (20%), and fracture (17%)

Clinical Features

• Pain/swelling over dorsal aspect of MCP joint (most commonly third, fourth, and/or fifth MCP joints)

Differential Diagnosis

• Hand and finger fractures

Hand and finger infections

• Bed bugs
• Closed fist infection (Fight Bite)
• Hand cellulitis
• Hand deep space infection
• Hand-foot-and-mouth disease
• Herpetic whitlow
• Felon
• Flexor tenosynovitis
• Paronychia
• Scabies
• Sporotrichosis

Look-Alikes

• Digital mixoid cyst

Diagnosis

• Imaging indicated to rule-out fracture, tooth fragments

Treatment

1. Copious irrigation
2. Wound left open to heal by secondary intention
   • May require loose approximation
3. Prophylactic antibiotics should be initiated for all but the most superficial wounds
   • If no visible signs of infection:
     • Amoxicillin/Clavulanate 875/125mg PO BID x5d
   • For signs of infection:
     • Ampicillin/Sulbactam 1.5gm IV q6h OR cefoxitin 2gm IV q8h OR Piperacillin/Tazobactam 3.375gm q6h
     • Penicillin allergy: clindamycin plus ciprofloxacin
     • Consider hand specialist consult for open irrigation and debridement with possible admission for IV abx

See Also

• Hand Infection
• Animal bites