II. Types
- Occlusive Bites
- Teeth penetrate and sink into skin
- Closed Fist (Fight Bite) - most common
- Laceration from fist contacting teeth
III. Pathophysiology
- Delayed presentation is common (wound appears mild initially)
IV. Mechanism: Hand is often injured in fist fight
- Known as Clenched-Fist Bite Wound or Fight Bite
- Index or Long finger MCP joint strikes tooth (typically upper teeth)
- Site of injury obscured in extension
- High risk for infection spread
- Often associated with small (3-5 mm) Laceration over MCP joint
- Associated injuries (in 75-100% of cases) despite initial benign, superficial appearance
- Penetrated tendon
- MCP joint capsule penetration
- Metacarpal head
- Extensor Tendon Injury
- Patzakis (1987) Clin Orthop Relat Res (220): 237-40 +PMID:3594996 [PubMed]
V. Risk Factors
- Fight Bites
- Young males
- Alcohol Intoxication
- Human Bites
- Assailants with psychiatric Illness or Developmental Delay
- Health care workers
- Law enforcement
VI. Causes: Organisms
- Most common
- Mixed Anaerobes and aerobes
- Staphylococcus aureus
- Streptococcus
- Bacteroides
- Fusobacterium
- Eikenella corrodens (anaerobic Gram Negative Rod)
- Rare, but case reports
- HIV Infection
- Hepatitis B Infection
VII. Signs: Fight Bite
- Laceration of 3-5 mm overlying the MCP joint, and less commonly, the (PIP joint)
VIII. Exam
- Thorough inspection
- Neurovascular evaluation
- Extensor tendon function (Elson Extensor Tendon Test)
- Cleansing and debridement is critical
- Extend Laceration as needed for full visualize
IX. Labs
- Anaerobic and aerobic cultures from wound
- Wound Gram Stain
X. Imaging: Clenched-Fist Bite Wound
- Finger XRay
- Fracture
- Osteomyelitis
- Foreign body
XI. Management
- Hand surgeon Consultation (Fight Bite)
- Discuss with local hand surgery
- Protocols vary by locale and per individual consultant
- Some experts recommend immediate admission, debridement, irrigation and parenteral antibiotics
- Tetanus prophylaxis
-
Hepatitis B Postexposure Prophylaxis
- Hepatitis B transmission has occurred with Human Bites (albeit rare)
- Prophylaxis Indicated if patient unimmunized and source cannot be tested or is suspected positive for Hepatitis B
- Give Hepatitis B immune globulin and Hepatitis B Vaccine
- Other Postexposure Prophylaxis
- HIV and Hepatitis C transmission are more rare than Hepatitis B transmission
- Transmission is possible if blood is in biter's Saliva
- Consider Infectious Disease Consultation regarding HIV Postexposure Prophylaxis indications
- Wound left open, and no structures are repaired
- Extensively irrigate wound
- Explore and debride wound under adequate lighting and exposure
- Extend Puncture Wounds in distal to proximal plane
- Remove foreign bodies
- Wick may be placed in wound, and removed the next day
- Splint hand in a position of function
- Apply Soft Bulky Dressing
- Antibiotics
- Precautions
- Obtain wound tissue for Gram Stain and culture prikor to antibiotics if possible
- Infections are most often polymicrobial
- Oral agents
- Amoxicillin-clavulanate (Augmentin) or
- Dicloxacillin with Penicillin (covers E. corrodens)
- Cephalexin (Keflex) with Penicillin or
- Clindamycin with Fluoroquinolone or
- Clindamycin with Trimethoprim-sulfamethoxazole
- Parenteral agents
- Indications
- Consider 1 parenteral dose and then oral
- Diabetes Mellitus
- Peripheral Vascular Disease
- Immunocompromised patient
- Wound older then 24 hours
- Signs of extensor tendon, capsule, or bone injury
- Systemic symptoms
- Concurrent Cellulitis
- Agents
- Ampicillin-sulbactam (Unasyn)
- Ticarcillin-clavulanate (Timentin)
- Cefoxitin (Mefoxin)
- Indications
- Precautions
- Daily Wound Cleansing and dressing changes
- if satisfactory healing:
- Antibiotics for 2-3 weeks
- if not improving then:
- Additional surgical debridement
- Consider IV antibiotics
- Complete Extensor Tendon Laceration
- Requires secondary repair
- Otherwise Secondary wound closure is not necessary
- if satisfactory healing:
- Outpatient Management Indications
- Indicated for wounds less than 24 hours old and no signs of infection
- Hospital management Indications
- Delayed presentation >24 hours after wound onset
- Immunocompromised state
- Systemic symptoms
- Joint capsule penetration
XII. References
- Cowling and House (2017) Crit Dec Emerg Med 31(5): 15-20
- Hori (2015) Crit Dec Emerg Med 29(3): 2-7
- Clark (2003) Am Fam Physician 68:2167-76 [PubMed]
- Presutti (1997) Postgrad Med 101(4): 243-54 [PubMed]
Images: Related links to external sites (from Bing)
Related Studies
| 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 |
| Russian | UKUSY CHELOVECHESKIE, УКУСЫ ЧЕЛОВЕЧЕСКИЕ |
| 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 |
