What is the recommended treatment for a cat scratch?

Treatment of Cat Scratches

For simple cat scratches without signs of infection, thorough wound cleansing with sterile normal saline is the primary intervention, with prophylactic amoxicillin-clavulanate 500-875 mg orally twice daily for 7-10 days recommended for deep wounds, wounds on hands/feet/face/near joints, or in immunocompromised patients. 1

Initial Wound Management

• Immediately cleanse all cat scratches thoroughly with sterile normal saline to remove superficial debris and reduce bacterial load 1
• Deeper debridement is typically unnecessary unless significant devitalized tissue is present 1
• Elevate the injured body part if swelling develops to accelerate healing 1
• Evaluate and update tetanus immunization status as needed 1
• Assess rabies risk for scratches from unknown or feral cats 1

Risk Stratification for Antibiotic Prophylaxis

Cat scratches carry approximately 10-20% infection risk (lower than bites at 30-50%) 1. Prophylactic antibiotics are indicated for:

• Deep wounds penetrating beyond the dermis 1
• Wounds on hands, feet, face, or near joints 1
• Immunocompromised patients (including diabetics, HIV-infected persons) 1
• Wounds with delayed presentation or early signs of infection 1

Antibiotic Selection

First-Line Therapy

Amoxicillin-clavulanate 500-875 mg orally twice daily for 7-10 days provides optimal coverage against Pasteurella multocida (present in cat saliva) and other common pathogens 2, 1

Penicillin-Allergic Patients

• Doxycycline 100 mg orally twice daily has excellent activity against P. multocida 2, 1
• Trimethoprim-sulfamethoxazole plus metronidazole (for anaerobic coverage) 1
• Fluoroquinolones (ciprofloxacin 500-750 mg twice daily) may require additional anaerobic coverage 1

Critical Pitfall

Avoid first-generation cephalosporins (e.g., cephalexin) due to poor activity against P. multocida 2

Treatment of Established Infection

Ascending Lymphangitis or Cellulitis

• Mild to moderate: Amoxicillin-clavulanate 875 mg orally twice daily for 7-10 days 2
• Severe infection: Ampicillin-sulbactam 1.5-3.0 g IV every 6-8 hours 2
• Monitor for complications including septic arthritis, osteomyelitis, and tendonitis, which require extended courses (4-6 weeks) 2

Cat Scratch Disease (Bartonella henselae)

If regional lymphadenopathy develops 3 weeks after a scratch (classic presentation), consider cat scratch disease 3:

• Most cases are self-limited and do not require antibiotics 4, 5, 6
• For symptomatic treatment or severe cases: Azithromycin is the antibiotic of choice 3, 4, 6
  • Adults >45 kg: 500 mg on day 1, then 250 mg daily for 4 additional days 3
  • Patients <45 kg: 10 mg/kg on day 1, then 5 mg/kg daily for 4 additional days 3
• Alternative effective agents include rifampin, ciprofloxacin, gentamicin, trimethoprim-sulfamethoxazole, and clarithromycin 4, 5

Special Populations

Diabetic Patients

• Require more aggressive treatment due to impaired immune response and delayed wound healing 1
• Treat mild soft tissue infections for 1-2 weeks, extending to 3-4 weeks if extensive or slow to resolve 1
• Provide optimal wound care including debridement of necrotic tissue and pressure off-loading 1
• Seek urgent surgical consultation for deep abscess, extensive necrosis, or necrotizing fasciitis 1

HIV-Infected/Immunocompromised Patients

• Should avoid rough play with cats and situations where scratches are likely 7
• Wash any cat-associated wound promptly 7
• Do not allow cats to lick open wounds or cuts 7
• Be vigilant for atypical presentations including bacillary angiomatosis 1
• Consider long-term suppression with erythromycin or doxycycline for recurrent Bartonella infection 7

Follow-Up Instructions

Patients must return immediately if signs of infection develop:

• Increasing pain, redness, or swelling 1
• Purulent drainage 1
• Fever 1
• Red streaking up the limb (lymphangitis) 2

Early and careful follow-up is essential to ensure treatment effectiveness, particularly in high-risk patients 1