Mammalian bites

Background

  • 5% of untreated dog bites will become infected (similar to rate of non-bite wounds)
  • 80% of untreated cat bites will become infected
  • Human Bite - (Also see Closed fist infection)

High-Risk Wounds

  • Cat, human, livestock, or monkey bites
  • Deep puncture wounds
  • Hand or foot wounds
  • Bites in immunosuppressed patients

Clinical Features

  • Depends on source of bite - bite marks or puncture wounds.

Differential Diagnosis

Envenomations, bites and stings

Evaluation

  • Clinical diagnosis, based on history and physical exam
  • Consider X-ray
    • If concern for retained foreign body (e.g. tooth)
    • To rule out fracture (adult dogs may exert >200 lbs force bite)
  • Consider Ultrasound
    • If concern for abscess or foreign body
  • CT Angio if concern for vascular injury
  • Wounds overlying a joint should be examined through complete range of motion to assess for tendon injury

Management

  • A mnemonic to remember management: HELICOPTER
    • History, Examination, Liberal cleansing, Irrigation, Closure & Culture consideration, Operative cleansing & closure, Prophylactic antibiotics, Tetanus immunization, Elevation, Rabies risk

Indications for Primary Closure of Mammalian Bites

  • Consider primary closure in face bites [1] [2] if all of the following are true:
    • Repair can occur within 6hr of injury (time dependent upon individual judgment)
    • Repair only requires single-layer closure; no devitalized tissue
    • No underlying fracture
    • No systemic immunocompromising conditions
  • Large gaping wounds outside the face may also require closure with loose approximation
  • Consider antibiotics in patients who are primarily closed

Antibiotics

Cat and Dog Bites

Coverage for Pasteurella, Strep, and Staph

  • Consider for high-risk wounds
    • wounds reaching the level of the muscle/tendon, wounds to the hand[3], violation of bone or joint capsule, immunocompromised hosts, wounds associated with significant local edema
  • Amoxicilin-clavulanate 875mg PO BID x 5-7 days OR[4]
  • Doxycycline 100mg PO daily x 14 days if penicillin allergic [5]
  • Clindamycin 450mg (5mg/kg) PO q8hrs daily x7 days PLUS

Human Bites

All human bites should be strongly considered for antibiotic therapy.[6]

Requires polymicrobial coverage for: S. aureus, Strep Viridans, Bacteroides, Coagulase-neg Staph, Eikenella, Fusobacterium, Cornebacterium, Peptostreptococcus

Mammalian Bites Severe Infections

Antivirals

  • Monkey Bites: Acyclovir or Valacyclovir
    • Monkeys are carriers of Cercopithecine herpesvirus 1 aka Herpesvirus simiae aka B virus.
    • Valacylovir — 1g PO q8hrs for 14 days or Acyclovir —800mg PO 5 times daily for 14 days

Rabies prophylaxis

  • Rabies immune globulin should be inidividualized[7]
    • Indicated for bites from bats, monkeys, skunks, raccoons, foxes. In the U.S. rare for dog and cat bites to contain rabies (however different rules apply for stray animal in areas with higher rabies incidence)
    • CDC recommends that if possible, the animal be tested, or quarantined for 10 days monitoring to help with the decision to provide rabies prophylaxis

Tetanus Prophylaxis

IDSA suggests considering Tetanus Vaccination in patients whose last Vx was 10 years or more [8]

Hand Bites

Extremity Wounds

Keep involved extremity elevated. Educate patient to avoid soaking the wound and avoid wrapping bandages too tightly.

See Also

Video

[[Category:WikEM]]

References

  1. Rui-feng C, Li-song Huang, Ji-bo Z, Li-qiu Wang. Emergency treatment on facial laceration of dog bite wounds with immediate primary closure: a prospective randomized trial study. BMC Emergency Medicine. 2013;13(Suppl 1):S2. doi:10.1186/1471-227X-13-S1-S2.
  2. Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the infectious diseases society of america. Clin Infect Dis. 2014 Jul 15;59(2):e10-52, executive summary can be found in Clin Infect Dis 2014 Jul 15;59(2):147
  3. EBQ:Antibiotic prophylaxis for mammalian bites
  4. Griego RD, Rosen T, Orengo IF, Wolf JE. Dog, cat, and human bites: a review. J Am Acad Dermatol. 1995;33:1019–29.
  5. Talan DA, Citron DM, Abrahamian FM, Moran GJ, Goldstein EJ. Bacteriologic analysis of infected dog and cat bites. Emergency Medicine Animal Bite Infection Study Group. N Engl J Med. 1999;340:85–92.
  6. EBQ:Antibiotic prophylaxis for mammalian bites
  7. Human rabies—Washington, D.C., 1995. MMWR Morb Mortal Wkly Rep. 1995;44:625–7.
  8. Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the infectious diseases society of america. Clin Infect Dis. 2014 Jul 15;59(2):e10-52, executive summary can be found in Clin Infect Dis 2014 Jul 15;59(2):147