Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA
Cat Bite Injuries and Cat Scratch Disease
Overview
- Cat bite injuries and cat scratch disease are distinct clinical conditions
- Cat bites:
- Higher infection risk than dog bites
- Dog bites:
- More common overall
Infection Rates
- Cat bites: 30–50% infection rate
- Dog bites: 2–5% infection rate
Demographics
- Cat bites – more common in females
- Dog bites – more common in males
- Common in:
- Children
- Frequently involve:
- Upper extremities
Cat Bite Injuries
Mechanism of Injury
- Cats have:
- Thin, sharp, needle-like teeth
Result
- Deep puncture wounds that may involve:
- Bone
- Joints
- Tendon sheaths (especially flexor sheath)
Important Feature
- Superficial wound closes quickly
- Bacteria remain trapped – high infection risk
Complications
- Abscess
- Septic arthritis
- Flexor tenosynovitis
- Osteomyelitis
Clinical Insight
- Injury often appears minor – delayed presentation common
Risk Factors for Infection
- Delay >12 hours
- Older age
- Deep puncture wounds
- Comorbidities:
- Diabetes
- Immunosuppression
Causative Organisms
Most Common
- Pasteurella multocida infection
Key Features
- Present in ~80% of cat bite wounds
- Rapid onset:
- Pain
- Swelling (within 48 hours)
Nature of Infection
- Often polymicrobial
Initial Management
- Thorough wound irrigation
- Tetanus prophylaxis
- Immobilization (if needed)
- Early antibiotics
- Close observation
Antibiotic Therapy
First-Line
- Amoxicillin-clavulanic acid
Indications
- Hand injuries
- Facial injuries
- Deep wounds
- Bone or joint involvement
Duration
- Typically 3–5 days (uncomplicated cases)
Surgical Management
Indications
- Abscess
- Septic arthritis
- Flexor tendon sheath infection
- Osteomyelitis
Procedure
- Incision and drainage
- Debridement
Cat Scratch Disease
Overview
- Infection caused by:
- Cat Scratch Disease
Causative Organism
- Bartonella henselae infection
Nature
- Usually:
- Benign
- Self-limiting
Clinical Course
- Cat scratch injury
- Skin lesion (~1 week)
- Lymph node enlargement (~2 weeks)
Lesion
- Small (<1 cm)
Symptoms
- Regional lymphadenopathy
- Fever
- Fatigue
- Headache
- Tender lymph nodes
- Occasionally suppuration
Common Lymph Nodes Involved
- Cervical
- Axillary
- Epitrochlear
- Inguinal
Clinical Note
- May mimic:
- Soft tissue tumors
Diagnosis
- History of cat exposure
- Regional lymph node enlargement
Laboratory Findings
- Elevated ESR
- Elevated CRP
Treatment
Most Cases
- Observation
- Symptomatic care
Antibiotics (if needed)
- Doxycycline
- Ciprofloxacin
- Azithromycin
Biopsy
- Rarely required
- May show:
- Necrotizing granulomas
Key Takeaways
- Cat bites:
- High risk of deep infection
- Require early treatment
- Pasteurella multocida:
- Most common pathogen
- Cat scratch disease:
- Self-limiting
- Presents with lymphadenopathy
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