What is the recommended management for a patient presenting with a cat bite, considering potential complications and individual patient factors such as immune status and bite severity?

Management of Cat Bites

For cat bite wounds, immediately initiate amoxicillin-clavulanate 875/125 mg twice daily as first-line therapy, as this provides optimal coverage against Pasteurella multocida (present in 75% of cat bites) and the polymicrobial flora characteristic of these injuries. 1, 2, 3

Immediate Wound Management

• Thoroughly irrigate all cat bite wounds with sterile normal saline and soap and water immediately to mechanically remove bacteria and reduce infection risk 1, 2
• Add povidone-iodine solution irrigation as a virucidal agent for additional antimicrobial effect 1
• Remove superficial debris but avoid aggressive debridement unless significant devitalized tissue is present 2, 4
• Do not primarily close infected wounds or deep puncture wounds as this traps bacteria and increases infection risk 2
• Elevate the injured extremity, especially if swollen, to accelerate healing 1, 2

Antibiotic Selection: Critical Decision Points

First-Line Therapy

• Amoxicillin-clavulanate 875/125 mg orally twice daily for 7-14 days is the definitive choice based on IDSA guidelines 1, 2, 3
• This regimen covers the polymicrobial nature of cat bites: P. multocida (75%), staphylococci/streptococci (40%), and anaerobes (65%) 1, 2

Alternative Regimens for Penicillin Allergy

• Doxycycline 100 mg twice daily is the preferred alternative with excellent P. multocida activity 1, 2, 3
• Fluoroquinolones (ciprofloxacin 500-750 mg twice daily or levofloxacin 750 mg daily) plus metronidazole for anaerobic coverage 1, 3
• Trimethoprim-sulfamethoxazole plus metronidazole as another combination option 1, 3

Critical Antibiotics to AVOID

Never use these as monotherapy for cat bites: 1, 2, 3

• First-generation cephalosporins (e.g., cephalexin) - poor P. multocida activity
• Penicillinase-resistant penicillins alone (e.g., dicloxacillin) - misses P. multocida
• Clindamycin alone - no P. multocida coverage
• Macrolides (e.g., erythromycin) - inadequate P. multocida activity

Indications for Hospitalization and IV Antibiotics

Admit and initiate IV therapy for: 2, 3

• Systemic signs of infection (fever, rigors, hypotension)
• Rapidly progressing cellulitis or lymphangitis
• Deep tissue involvement (tenosynovitis, septic arthritis, osteomyelitis)
• Hand wounds with signs of deep infection
• Immunocompromised hosts with moderate-to-severe injuries

IV Antibiotic Options

• Ampicillin-sulbactam 1.5-3.0 g every 6-8 hours as first-line IV therapy 1, 3
• Piperacillin-tazobactam, second-generation cephalosporins (cefoxitin), or carbapenems as alternatives 1, 2

High-Risk Scenarios Requiring Prophylactic Antibiotics

Always prescribe prophylactic antibiotics for: 2, 3

• Deep puncture wounds (cat teeth create narrow, deep wounds prone to infection)
• Wounds on hands, feet, face, or near joints
• Wounds presenting >8-12 hours after injury
• Immunocompromised patients (diabetes, asplenia, liver disease, HIV)
• Any wound with early signs of infection (erythema, warmth, purulent drainage)

Special Consideration: Hand Wounds

• Cat bites to the hand carry the highest risk of serious complications including septic arthritis, osteomyelitis, and flexor tenosynovitis 2, 3, 5
• These wounds often appear deceptively minor externally but penetrate deeply into joint spaces and tendon sheaths 6, 5
• Maintain a low threshold for hospitalization with hand wounds showing any signs of infection 5

Rabies and Tetanus Prophylaxis

Rabies Assessment

• If the cat is healthy and available, confine and observe for 10 days 1
• Begin rabies postexposure prophylaxis (RIG plus vaccine series) immediately if the cat is stray, unwanted, or shows signs of rabies 1, 7
• Euthanize and test any cat showing neurological signs during observation 1
• For unprovoked attacks or unknown vaccination status cats, strongly consider rabies prophylaxis 1

Tetanus Prophylaxis

• Update tetanus immunization if status is outdated or unknown 1, 2

Follow-Up Protocol

• All outpatients must be reassessed within 24 hours either by phone or office visit 2
• Instruct patients to return immediately for: 2, 3
  • Increasing pain, redness, or swelling
  • Purulent drainage
  • Fever or chills
  • Decreased range of motion (especially hand wounds)
  • Red streaking (lymphangitis)

Common Pitfalls to Avoid

• Do not rely on topical antibiotics alone - cat bites require systemic coverage due to deep inoculation 2
• Do not delay treatment - infections can develop within 3-12 hours and progress rapidly to deep tissue complications 5, 8
• Do not underestimate seemingly minor puncture wounds - external appearance does not correlate with depth of bacterial inoculation 6, 5
• Do not use mupirocin for deep cat bite infections - it has excellent staphylococcal activity but inadequate penetration for deep-seated infections 2

Duration of Therapy

• 3-5 days for prophylaxis of uncomplicated wounds 3
• 7-14 days for established infections 2, 3
• Consider extending to 3-4 weeks for extensive infections, slow resolution, or patients with severe peripheral artery disease 4