From the Guidelines
Azithromycin is the preferred antibiotic for cat scratch skin infections, administered at 500mg on day one followed by 250mg daily for 4 additional days for patients weighing ≥45.5 kg, and 10 mg/kg on day 1 and 5 mg/kg for 4 more days for those weighing <45.5 kg, as recommended by the Infectious Diseases Society of America 1.
Key Considerations
- The treatment targets Bartonella henselae, the bacterium commonly responsible for cat scratch disease.
- Most cases of cat scratch disease are self-limiting and may not require antibiotics, but treatment is recommended for more severe infections or in immunocompromised patients.
- In addition to antibiotics, it is essential to clean the wound thoroughly with soap and water immediately after the scratch occurs, and apply an antiseptic.
Monitoring and Follow-up
- Watch for signs of worsening infection such as increasing redness, warmth, swelling, or fever, which may indicate a need for medical evaluation.
- If lymph nodes become significantly enlarged or painful, or if symptoms persist beyond two weeks, consult a healthcare provider for possible adjustment of treatment.
Evidence-Based Recommendation
The recommendation for azithromycin is based on a strong, moderate-quality evidence from the Infectious Diseases Society of America 1, which suggests that azithromycin is effective in reducing lymph node size and improving symptoms in patients with cat scratch disease. A single, double-blind placebo-controlled study also supports the use of azithromycin, showing that lymph node size regressed by 80% at 30 days more frequently in azithromycin-treated patients (P = .02) 1.
From the Research
Preferred Antibiotics for Cat Scratch Skin
- The most effective antibiotics for treating cat scratch disease include rifampin, ciprofloxacin, gentamicin, trimethoprim and sulfamethoxazole, clarithromycin, and azithromycin 2.
- Azithromycin has been shown to speed recovery in patients with cat scratch disease 2, 3.
- For persistent B. henselae infections, drug combinations such as azithromycin/ciprofloxacin, azithromycin/methylene blue, rifampin/ciprofloxacin, and rifampin/methylene blue have been found to be effective in killing stationary phase and biofilm recovered cells of B. henselae 4.
- Gentamicin and doxycycline are recommended for treating Bartonella spp. bacteraemia, while gentamicin in combination with doxycycline is considered the best treatment regimen for endocarditis 5.
- Erythromycin is the first-line antibiotic therapy for the treatment of angioproliferative lesions, and rifampicin or streptomycin can be used to treat verruga peruana 5.
Treatment Considerations
- Most cases of cat scratch disease are self-limited and do not require antibiotic treatment 2, 3.
- Treatment is recommended in rare cases where Bartonella actually causes disease, such as in immunocompromised individuals or in cases of severe infection 6.
- The severity of Bartonella infection correlates with the patient's immune status, and clinical manifestations can range from benign and self-limited to severe and life-threatening disease 5.