Management of Indoor Cat Scratches and Bites
For minor scratches from an indoor cat in an immunocompetent person, thoroughly cleanse the wound with sterile normal saline and observe without antibiotics unless the wound is deep, on the hand/foot/face/near joints, or shows signs of infection—in which case start amoxicillin-clavulanate 875/125 mg twice daily for 7-10 days. 1, 2
Initial Wound Assessment and Care
Immediate Management
- Thoroughly cleanse all cat scratches with sterile normal saline to remove superficial debris and reduce infection risk 1, 2
- Deeper debridement is unnecessary unless significant devitalized tissue is present 1
- Evaluate tetanus immunization status and update if needed 1
Risk Stratification for Infection
Cat scratches carry approximately 10-20% infection risk (compared to 30-50% for actual bites), making selective antibiotic use appropriate 1
When to Use Prophylactic Antibiotics
High-Risk Wounds Requiring Antibiotics
Prophylactic antibiotics are indicated for: 1, 2
- Deep wounds or puncture wounds
- Wounds on hands, feet, face, or near joints
- Immunocompromised patients
- Signs of infection developing (erythema >5 cm, warmth, purulent drainage, red streaking, fever ≥38.5°C) 2
Low-Risk Wounds (Observation Only)
Minor superficial scratches in immunocompetent patients can be observed without antibiotics after proper wound cleansing 1, 3
Antibiotic Selection
First-Line Therapy
Amoxicillin-clavulanate 875/125 mg orally twice daily for 7-10 days is the preferred regimen, providing optimal coverage against Pasteurella multocida and other common pathogens from cat scratches 1, 2
Penicillin-Allergic Patients
Alternative options include: 1
- Doxycycline 100 mg twice daily (excellent Pasteurella activity)
- Fluoroquinolones: ciprofloxacin 500-750 mg twice daily or levofloxacin 750 mg daily
- Trimethoprim-sulfamethoxazole plus metronidazole (for combined aerobic/anaerobic coverage)
Critical Pitfall to Avoid
Never use first-generation cephalosporins (e.g., cephalexin) for cat scratches due to poor activity against P. multocida 2
Clindamycin should not be used as monotherapy because it lacks adequate Pasteurella coverage despite good activity against staphylococci and anaerobes 1
Cat Scratch Disease (Bartonella henselae)
When to Suspect
Consider cat scratch disease if regional lymphadenopathy develops 1-3 weeks after the scratch, particularly epitrochlear or axillary nodes 2
Treatment for Cat Scratch Disease
Azithromycin is the treatment of choice: 1, 2
- Adults (>45 kg): 500 mg on day 1, then 250 mg daily for 4 additional days
- Children (<45 kg): 10 mg/kg on day 1, then 5 mg/kg daily for 4 additional days
Important note: Most cases of cat scratch disease in immunocompetent hosts resolve without antibiotics, but azithromycin accelerates lymph node resolution 3, 4
Follow-Up and Monitoring
Reassessment Timeline
Reassess in 48-72 hours to ensure antibiotic efficacy and clinical improvement 2
Warning Signs Requiring Return
Advise patients to return immediately if: 1
- Increasing pain, redness, or swelling
- Purulent drainage develops
- Red streaking (lymphangitis)
- Fever develops
- Hand wounds showing signs of deep infection (risk of septic arthritis, osteomyelitis, tendonitis) 1, 2
Special Considerations for Indoor Cats
Rabies Risk Assessment
Indoor cats from known households pose minimal rabies risk and typically do not require rabies prophylaxis 1
Consider rabies assessment only for scratches from unknown or feral cats 1
Prevention Counseling
For patients with indoor cats: 5
- Keep cats indoors and prevent hunting
- Maintain flea control to reduce Bartonella transmission risk
- Avoid activities that provoke scratching or biting
- Wash hands after handling cats
- Do not allow cats to lick open wounds
Immunocompromised Patients
Immunocompromised individuals require more aggressive management with lower threshold for antibiotic initiation, as they risk atypical presentations including bacillary angiomatosis and disseminated disease 5, 1, 6, 4