II. Mechanism: Hand is often injured in fist fight

  1. Known as Clenched-fist Injury or Fight Bite
  2. Index or Long finger MCP joint strikes tooth
    1. Site of injury obscured in extension
    2. High risk for infection spread
    3. Often associated with small (5 mm) Laceration over MCP joint
  3. Associated injuries (in 75% of cases) despite initial benign, superficial appearance
    1. Penetrated tendon
    2. MCP joint capsule
    3. Metacarpal head
    4. Extensor Tendon Injury
    5. Patzakis (1987) Clin Orthop Relat Res (220): 237-40 +PMID:3594996 [PubMed]

III. Etiologies

  1. Most common
    1. Mixed Anaerobes and aerobes
    2. Staphylococcus aureus
    3. Streptococcus
    4. Bacteroides
    5. Fusobacterium
    6. Eikenella corrodens (anaerobic Gram Negative Rod)
  2. Rare, but case reports
    1. HIV Infection
    2. Hepatitis B Infection

IV. Signs

  1. Thorough inspection
    1. Neurovascular evaluation
    2. Extensor tendon function
  2. Cleansing and debridement is critical
  3. Extend Laceration as needed for full visualize

V. Labs

  1. Anaerobic and aerobic cultures from wound
  2. Wound Gram Stain

VI. Imaging: Finger XRay

  1. Fracture
  2. Osteomyelitis
  3. Foreign body

VII. Management

  1. Hand surgeon Consultation
    1. Discuss with local hand surgery
    2. Protocols vary by locale and per individual consultant
    3. Some experts recommend immediate admission, debridement, irrigation and parenteral antibiotics
  2. Tetanus prophylaxis
  3. Wound left open, and no structures are repaired
  4. Explore, irrigate, and debride wound under adequate lighting and exposure
    1. Extend Puncture Wounds in distal to proximal plane
  5. Wick may be placed in wound, and removed the next day
  6. Apply Soft Bulky Dressing
  7. Antibiotics
    1. Oral agents
      1. Amoxicillin-clavulanate (Augmentin) or
      2. Dicloxacillin with Penicillin (covers E. corrodens)
      3. Cephalexin (Keflex) with Penicillin or
      4. Clindamycin with Fluoroquinolone or
      5. Clindamycin with Trimethoprim-sulfamethoxazole
    2. Parenteral agents
      1. Indications
        1. Consider 1 parenteral dose and then oral
        2. Diabetes Mellitus
        3. Peripheral Vascular Disease
        4. Immunocompromised patient
        5. Wound older then 24 hours
        6. Signs of extensor tendon, capsule, or bone injury
        7. Systemic symptoms
        8. Concurrent Cellulitis
      2. Agents
        1. Ampicillin-sulbactam (Unasyn)
        2. Ticarcillin-clavulanate (Timentin)
        3. Cefoxitin (Mefoxin)
  8. Daily Wound Cleansing and dressing changes
    1. if satisfactory healing:
      1. Antibiotics for 2-3 weeks
    2. if not improving then:
      1. Additional surgical debridement
      2. Consider IV antibiotics
    3. Complete Extensor Tendon Laceration
      1. Requires secondary repair
      2. Otherwise Secondary wound closure is not necessary
  9. Inpatient Management
    1. Indicated for wound older than a few hours

Images: Related links to external sites (from Bing)

Related Studies (from Trip Database) Open in New Window

Ontology: Human Bite (C0005660)

Definition (MSH) Bites inflicted by humans.
Concepts Injury or Poisoning (T037)
MSH D001734
ICD9 E928.3
ICD10 W50.3
SnomedCT 157940004, 242605002, 43028005
English Bite, Human, Bites, Human, Human Bites, human bites (diagnosis), human bites, Human bite - accidental, Bites, Human [Disease/Finding], Bite;human, bite human, biting humans, bites human, bites humans, Human bite (disorder), Human bite, Human bite (morphologic abnormality), bite; human, human; bite, Human Bite, human bite, Human bite (finding), Human bite (event)
Spanish mordedura de humano (evento), mordedura de humano (hallazgo), mordedura de humano, mordedura humana (anomalía morfológica), mordedura humana, Mordedura humana, Mordeduras Humanas
Italian Morso umano, Morsi umani
Japanese 人による咬傷, ヒトニヨルコウショウ
Swedish Människobett
Czech kousnutí člověkem, Kousnutí člověkem
Finnish Ihmisen puremat
Polish Ukąszenie przez człowieka, Ugryzienie przez człowieka
Hungarian Emberi harapás
Norwegian Menneskebitt
Dutch beet; humaan, humaan; beet, mensenbeet, Beet, mensen-, Beten, mensen-, Mensenbeet, Mensenbeten
Portuguese Mordedura humana, Mordeduras Humanas
French Morsure humaine, Morsures humaines
German Menschenbiss, Bisse, menschliche, Menschenbisse