What is the recommended antibiotic regimen for Cat Scratch Disease (CSD)?

From the Guidelines

The recommended antibiotic regimen for cat scratch disease is azithromycin, typically 500 mg on day one followed by 250 mg daily for 4 more days in adults, as supported by the Infectious Diseases Society of America guidelines 1. This recommendation is based on the strongest and most recent evidence available, which suggests that azithromycin is effective in reducing lymph node size and alleviating symptoms in patients with cat scratch disease.

Key Considerations

• The dosing protocol for azithromycin is as follows:
  • Patients weighing ≥45.5 kg (100 lb): 500 mg on day 1, then 250 mg once daily for 4 additional days 1
  • Patients weighing <45.5 kg: 10 mg/kg orally on day 1, then 5 mg/kg on days 2–5 1
• Alternative antibiotics, such as doxycycline, ciprofloxacin, or trimethoprim-sulfamethoxazole, may be considered in certain cases, but azithromycin is the preferred choice due to its efficacy and safety profile 1
• It is essential to note that most cases of cat scratch disease are self-limiting and may not require antibiotics, but treatment is recommended for severe or systemic symptoms, lymph node involvement that persists beyond 2-3 months, or in immunocompromised patients 1
• In addition to antibiotics, supportive care with warm compresses and over-the-counter pain relievers like acetaminophen or ibuprofen can help manage symptoms, and needle aspiration may provide relief for severely painful or suppurative lymph nodes 1

From the Research

Antibiotic Regimen for Cat Scratch Disease

The antibiotic regimen for cat scratch disease is as follows:

• Azithromycin has been shown to be effective in treating cat scratch disease, with one study finding that it sped up recovery 2.
• Trimethoprim/sulfamethoxazole (TMP/SMX) is also effective, with a study finding that it had comparable effectiveness to azithromycin 3.
• Other antibiotics that have been shown to be effective against Bartonella henselae, the bacterium that causes cat scratch disease, include rifampin, ciprofloxacin, gentamicin, clarithromycin, and erythromycin 4, 5.
• However, it's worth noting that most cases of cat scratch disease are self-limited and do not require antibiotic treatment 4, 5, 2.

Specific Patient Populations

• In immunocompromised patients, antibiotic therapy may be necessary to prevent serious complications such as bacillary angiomatosis, bacillary peliosis, and relapsing bacteremia 4, 5.
• In pediatric patients, azithromycin and TMP/SMX have been shown to be effective in treating cat scratch disease 3.

Treatment Guidelines

• The choice of antibiotic should be based on the severity of the disease and the patient's individual needs 4, 5.
• Treatment should be guided by clinical judgment and laboratory results, including serologic tests and culture results 2, 6.