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Basics

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Author:

Daniel T.Wu


Description!!navigator!!

Etiology!!navigator!!

Diagnosis

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Signs and Symptoms!!navigator!!

History

  • Animal's behavior, provocation, location, ownership
  • Time since attack
  • Past medical history: Conditions compromising immune function, allergies, and tetanus status

Physical Exam

  • Record the location and extent of all injuries
  • Document any swelling, crush injuries, or devitalized tissue
  • Note the range of motion of affected areas
  • Note the status of tendon and nerve function
  • Document any signs of infection, including regional adenopathy
  • Document any joint or bone involvement

Diagnostic Tests & Interpretation!!navigator!!

Lab

  • Aerobic and anaerobic cultures from any infected bite wound
  • Cultures not routinely indicated if wounds not clinically infected
  • CSD:
    • Presence of elevated titers of B. (Rochalimaea) henselae, or
    • Positive reaction to cat scratch antigen (CSA):
      • Inject 0.1 mL CSA IM
      • Induration at the site 48-72 hr later equal to or exceeding 5 mm is positive

Imaging

Plain radiograph indications:

  • Fracture
  • Suspect foreign body (e.g., tooth)
  • Baseline film if a bone or joint space has been violated in evaluating for osteomyelitis
  • For infection in proximity to a bone or joint space

Differential Diagnosis!!navigator!!

Treatment

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Prehospital!!navigator!!

Apply pressure to any bleeding wound

Initial Stabilization/Therapy!!navigator!!

ED Treatment/Procedures!!navigator!!

Medication!!navigator!!

First Line

  • Amoxicillin/clavulanic acid (Augmentin): 500/125 mg (peds: 40 mg/kg/24 hr) q8h PO
  • Ampicillin-sulbactam (Unasyn): 3 g q6h IV
  • Penicillin G 1-2 million units q6h IV (peds: 20,000-50,000 units/kg/d div. q4h IV)
  • Piperacillin-Tazobactam (Zosyn): 4.5 g q8h IV
  • Ticarcillin-clavulanate (Timentin): 3.1 g q4h IV
  • Ceftriaxone (Rocephin): 1 g/d IV or IM plus metronidazole (Flagyl): 500 mg q8h IV

Second Line

  • 2 drug therapy: 1 of the following below + anaerobic coverage:
    • Trimethoprim-sulfamethoxazole (Septra DS): 1 tablet q12h (peds: 8 mg/kg trimethoprim and 40 mg/kg sulfamethoxazole per day divided into 2 daily doses) PO
    • Penicillin (Penicillin VK): 500 mg (peds: 50 mg/kg/24 hr) PO q6h
    • Ciprofloxacin (Cipro): 500-750 mg q12h PO or 400 mg q12h IV
    • Doxycycline: 100 mg PO b.i.d
  • + (anaerobic coverage):
    • Clindamycin (Cleocin): 150-450 mg (peds: 8-20 mg/kg/24 hr) PO q6h or 600-900 mg (peds: 20-40 mg/kg/24 hr) IV q8h
    • Metronidazole (Flagyl): 500 mg PO t.i.d (peds: 10 mg/kg/dose t.i.d)

Follow-Up

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Disposition!!navigator!!

Admission Criteria

  • All bites:
    • Extensive infected wounds at presentation
    • Severe/advancing cellulitis/lymphangitis
    • Signs of systemic infection
    • Infected wounds that have failed to respond to outpatient (PO) antibiotics
  • CSD:
    • Prolonged fever, systemic symptoms, and /or marked lymphadenopathy

Discharge Criteria

  • Healthy patient with localized wound infection:
    • Discharge on antibiotics with 24-hr follow-up
  • Noninfected wounds:
    • 48-hr follow-up

Follow-up Recommendations!!navigator!!

Pearls and Pitfalls

Animal bites must be reported to authorities in many localities

Additional Reading

See Also (Topic, Algorithm, Electronic Media Element)

Rabies

Codes

ICD9

ICD10

SNOMED