Animal Exposure Category and Management
This is a Category II rabies exposure (nonbite exposure with skin break), and you should immediately initiate wound care, administer tetanus booster, consider rabies post-exposure prophylaxis pending cat observation, and consider antibiotic prophylaxis for cat-scratch disease.
Rabies Exposure Classification
This superficial scratch with skin break from a stray cat constitutes a Category II exposure according to WHO/ACIP classification. The key factor is that the scratch broke the skin, creating a potential rabies transmission route 1.
Immediate Wound Management
Thoroughly irrigate the wound immediately with water or dilute povidone-iodine solution 1. This is critical because wound cleansing alone markedly reduces rabies risk in animal studies 1. Avoid aggressive scrubbing that damages tissue. Do not suture the wound 1.
Rabies Post-Exposure Prophylaxis Decision
The decision hinges on whether the cat can be observed:
If Cat Can Be Captured and Observed (10 Days)
- Defer rabies prophylaxis initially
- Confine and observe the cat for 10 days 1
- If the cat remains healthy for 10 days, no rabies prophylaxis needed
- If the cat develops signs of rabies or dies during observation, immediately initiate full post-exposure prophylaxis (HRIG + 5-dose vaccine series)
If Cat Cannot Be Captured (Most Likely Scenario for Stray)
Initiate rabies post-exposure prophylaxis immediately because:
- The cat is a stray with unknown vaccination status
- Cannot be observed for 10 days
- Scratches from cats can transmit rabies 2, 3
The regimen for previously unvaccinated persons:
- Human Rabies Immune Globulin (HRIG): 20 IU/kg body weight, infiltrate as much as possible around the wound, inject remainder IM at distant site 1
- Rabies vaccine: 5 doses (1 mL IM in deltoid) on days 0,3,7,14, and 28 1
Critical pitfall: HRIG and first vaccine dose must NEVER be given in the same anatomical site 1. HRIG can only be given up to day 7 of the series 1.
Tetanus Prophylaxis
Administer tetanus booster immediately 1, 4. Since her last tetanus was >10 years ago:
- Give Tdap (preferred over Td) if she has never received Tdap 4
- This is a "dirty wound" with animal exposure, requiring booster if >5 years since last dose 4
Important note: Even previously immunized patients can develop tetanus from cat scratches, though severity is modulated by prior vaccination 5.
Cat-Scratch Disease Prophylaxis
Consider antibiotic prophylaxis given the skin break and stray cat exposure. While most immunocompetent patients with cat-scratch disease don't require antibiotics 6, prophylaxis is reasonable for:
- Fresh wounds with skin break
- Unknown cat health status
- Prevention of Bartonella henselae infection
Recommended prophylactic regimen:
- Azithromycin 500 mg PO once, then 250 mg daily for 4 days (most evidence-based) 6, 7
- Alternative: Doxycycline 100 mg PO twice daily for 7-10 days
The wound location (first digit) makes infection risk higher, as hand wounds have increased infection rates 4.
Bacterial Infection Prophylaxis
Prescribe amoxicillin-clavulanate 875/125 mg PO twice daily for 3-5 days 4. Cat scratches carry polymicrobial flora including Pasteurella multocida, anaerobes, and other pathogens. Amoxicillin-clavulanate provides appropriate coverage for typical cat-associated organisms 4.
If penicillin allergic: Moxifloxacin 400 mg daily OR (ciprofloxacin 500 mg twice daily + metronidazole 500 mg twice daily) 4.
Follow-Up Instructions
- Monitor wound for signs of infection (erythema, warmth, purulent drainage, lymphangitis)
- Watch for lymphadenopathy developing 1-3 weeks post-exposure (cat-scratch disease) 6, 8
- If rabies prophylaxis initiated, ensure completion of full 5-dose series
- Return immediately if neurological symptoms develop (rabies incubation can be weeks to months) 1
Common pitfall: Do not close or approximate this wound, even though it's on the hand. Primary closure increases infection risk for hand wounds 4.