From the Guidelines
The recommended treatment for cat-scratch disease is azithromycin, with a dosing protocol of 500 mg on day 1 followed by 250 mg 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 patients weighing <45.5 kg, as supported by the Infectious Diseases Society of America guidelines 1. This approach is based on the effectiveness of azithromycin in targeting Bartonella henselae, the causative bacterium of cat-scratch disease, which has been shown to respond well to macrolides that inhibit bacterial protein synthesis. Some key points to consider in the treatment of cat-scratch disease include:
- The disease often resolves on its own within 2-4 months in immunocompetent patients with mild to moderate disease, but azithromycin can be used to reduce lymph node size and alleviate symptoms 1.
- Alternative antibiotics such as trimethoprim-sulfamethoxazole, ciprofloxacin, or rifampin may be considered in certain cases, but azithromycin is the first-line treatment 1.
- Symptomatic treatment, including warm compresses and over-the-counter pain relievers, can help manage discomfort and reduce the risk of complications 1.
- In cases with suppurative lymphadenitis, needle aspiration may be necessary to drain pus and relieve pressure, and severe complications such as neuroretinitis or encephalitis may require more aggressive antibiotic therapy and longer treatment duration 1.
From the Research
Diagnosis of Cat-Scratch Disease
- Cat-scratch disease (CSD) is typically diagnosed by obtaining a history of exposure to cats and a serologic test with high titers of immunoglobulin G antibody to B. henselae 2
- The causative microorganism, B. henselae, is difficult to culture, and either serology or the polymerase chain reaction are considered to be the best methods of detection 3
Treatment of Cat-Scratch Disease
- The majority of CSD cases resolve spontaneously and do not require antibiotic treatment 3, 4, 5, 2
- In complicated CSD, treatment with trimethoprim-sulphamethoxazole, ciprofloxacin, or azithromycin is recommended, with gentamicin being reserved for the severely ill patient 3
- Azithromycin therapy has been associated with more rapid diminution in size of infected lymph nodes 4
- In immunocompromised patients, treatment with trimethoprim-sulfamethoxazole and doxycycline may be effective, with a reduction in immunosuppressive therapy 6
Special Considerations
- Immunocompromised individuals, particularly organ transplant recipients, are at increased risk of severe infections with potential multisystem involvement 6
- Hepatosplenic Bartonella infection in renal transplant recipients may require prolonged antimicrobial therapy, and an individualized treatment duration should be considered 6
- Imaging modalities play a crucial role in monitoring treatment response in immunocompromised patients 6