Does a healthy 56-year-old require rabies post-exposure prophylaxis (PEP) and antibiotic prophylaxis after a provoked otter bite?

Management of Otter Bite in a Healthy 56-Year-Old

Rabies post-exposure prophylaxis (PEP) is recommended for this patient despite the provoked nature of the otter bite, and antibiotic prophylaxis should be administered due to the high risk of infection from animal bites. 1

Rabies Risk Assessment

Animal-Specific Considerations

• Otters are wild animals that should be regarded as potentially rabid unless proven negative by laboratory testing
• The CDC recommends immediate prophylaxis for bites from wild carnivores 1
• Even though the attack was provoked, which generally indicates lower risk, wild animals carry a higher baseline risk of rabies

Exposure Assessment

• Any penetration of skin by teeth constitutes a bite exposure requiring evaluation for rabies PEP 2
• The site of the bite should not influence the decision to begin treatment, though bites to face and hands carry highest risk 2

Recommended Management

Immediate Wound Care

• Thoroughly wash and flush all wounds with soap/cleansing agent and water for approximately 15 minutes 1
• Apply iodine-containing or viricidal topical preparation to the wound
• This initial wound cleansing significantly reduces rabies risk but is not sufficient without appropriate vaccination 1

Rabies Post-Exposure Prophylaxis

• For a previously unvaccinated person:
  • Human Rabies Immune Globulin (HRIG): 20 IU/kg body weight, infiltrated around and into wounds 1
  • Rabies vaccine: Five 1-mL doses administered intramuscularly in the deltoid on days 0,3,7,14, and 28 1
• If the animal can be captured and tested negative for rabies, PEP can be discontinued 1

Antibiotic Prophylaxis

• Antibiotic prophylaxis is recommended for animal bites, especially those from wild animals 1
• Appropriate options include:
  • Amoxicillin-clavulanate (first-line)
  • Alternatives for penicillin-allergic patients: doxycycline or trimethoprim-sulfamethoxazole plus clindamycin

Tetanus Prophylaxis

• Administer tetanus toxoid if the patient has not received a booster within the past 5 years 1
• For patients with unknown or incomplete tetanus vaccination history, administer tetanus immune globulin in addition to tetanus toxoid

Important Considerations

Timing of PEP

• PEP is a medical urgency, not an emergency, but should not be unnecessarily delayed 1
• The effectiveness of PEP decreases as the interval between exposure and treatment increases
• HRIG can still be administered up to 7 days after the first vaccine dose if not given initially 2

Potential Pitfalls

• Undertreatment risk: Failing to provide prophylaxis for high-risk exposures can be fatal as rabies is nearly 100% lethal once symptoms develop 1
• Compliance concerns: Ensure patient understands the importance of completing the full vaccination series 3
• HRIG administration errors: HRIG should never be administered in the same syringe or anatomical site as the first vaccine dose 1

Follow-up

• Ensure the patient returns for all scheduled vaccine doses
• Monitor the wound for signs of infection
• Report the bite to local public health authorities who may attempt to locate and test the animal

While the attack was provoked, which typically suggests lower risk, the wild nature of the animal (otter) places this bite in a higher risk category that warrants full rabies PEP unless the animal can be captured and tested negative for rabies.