How should I manage swollen cat bite and scratch wounds?

Treatment for Swollen Cat Bites and Scratches

For swollen cat bites and scratches, start oral amoxicillin-clavulanate immediately, elevate the affected limb, and seek medical attention within 48 hours to prevent serious complications including osteomyelitis, septic arthritis, and potential amputation. 1, 2

Immediate Wound Management

Wound cleansing is critical and should be performed immediately:

• Irrigate thoroughly with sterile normal saline or soap and water—this alone markedly reduces infection risk 1, 3, 4
• Remove superficial debris but avoid aggressive debridement that could enlarge the wound 1
• Do NOT suture infected or swollen wounds—infected wounds should remain open 1
• Approximation with Steri-Strips may be acceptable for non-infected wounds, but primary closure increases infection risk 1

Antibiotic Therapy

First-line treatment (oral, outpatient):

• Amoxicillin-clavulanate 500-875 mg twice daily is the recommended first-line agent 1
• This covers the critical pathogens: Pasteurella multocida (present in 75% of cat bites), anaerobes (65% of cat bites), staphylococci, and streptococci 1

Alternative oral regimens if amoxicillin-clavulanate cannot be used:

• Doxycycline 100 mg twice daily (excellent activity against P. multocida) 1
• Penicillin VK 500 mg four times daily PLUS dicloxacillin 500 mg four times daily 1
• Fluoroquinolones (ciprofloxacin 500-750 mg twice daily, levofloxacin, or moxifloxacin) PLUS metronidazole or clindamycin for anaerobic coverage 1

Antibiotics to AVOID:

• Never use cephalexin, dicloxacillin alone, macrolides, or clindamycin alone—these have poor activity against P. multocida and should be avoided 1

Intravenous therapy (for severe infections requiring hospitalization):

• Ampicillin-sulbactam 1.5-3.0 g every 6-8 hours 1
• Piperacillin-tazobactam 3.37 g every 6-8 hours 1
• Carbapenems (ertapenem 1 g daily, imipenem 1 g every 6-8 hours, or meropenem 1 g every 8 hours) 1

Critical Adjunctive Measures

Elevation is essential for swollen wounds:

• Elevate the injured body part, especially if swollen, during the first few days after injury—this accelerates healing 1
• Use a sling for outpatients or tubular stockinet with IV pole for inpatients 1

Timing and Follow-Up

The 48-hour window is critical:

• Patients presenting within 48 hours have significantly better outcomes with mean hospital stay of 3.4 days 2
• Delayed presentation beyond 48 hours results in 78% requiring multiple operations, mean hospital stay of 9.2 days, and risk of amputation 2
• Follow up within 24 hours by phone or office visit 1
• If infection progresses despite appropriate therapy, hospitalization is required 1

High-Risk Features Requiring Urgent Attention

Seek immediate medical care if:

• Hand or wrist wounds (45% involve the index finger; 40% develop flexor tendon sheath infections) 2
• Pain disproportionate to injury near bone or joint—suggests periosteal penetration, osteomyelitis, or septic arthritis 1
• Diabetic patients or immunocompromised individuals (higher amputation risk) 2
• Signs of systemic infection (fever, lymphangitis, rapidly progressive swelling) 5

Serious Complications to Monitor

Cat bites are more severe than dog bites despite less tissue trauma:

• Higher rates of osteomyelitis and septic arthritis 1
• Complications include septic arthritis, osteomyelitis, subcutaneous abscess, tendonitis, and bacteremia 1
• These complications require prolonged therapy: 4-6 weeks for osteomyelitis, 3-4 weeks for synovitis 1
• Four patients in one series required digital or ray amputations due to delayed presentation 2

Additional Considerations

Tetanus prophylaxis:

• Administer tetanus toxoid if not vaccinated within 10 years 6
• For dirty wounds, give booster if >5 years since last dose 6

Rabies evaluation:

• Consider rabies postexposure prophylaxis based on animal vaccination status and local epidemiology 3, 4
• Wound treatment and vaccination are essential components if rabies exposure is suspected 3, 4

Common pitfall: The overall infection rate for cat bites is 15.6%, with puncture wounds and full-thickness wounds at highest risk 7. The presence of swelling indicates established infection requiring immediate antibiotic therapy—do not delay treatment.