Pediatric Dosing for Cat Scratch Disease
Azithromycin is the recommended first-line treatment for pediatric cat scratch disease, with a dosage of 10 mg/kg on day 1 followed by 5 mg/kg for 4 additional days in children <45 kg. 1
Recommended Antibiotic Options
First-Line Treatment:
- Azithromycin:
- Children <45 kg: 10 mg/kg on day 1, then 5 mg/kg for 4 more days
- Children >45 kg: 500 mg on day 1, then 250 mg for 4 more days
Alternative Options (if azithromycin cannot be used):
Trimethoprim-sulfamethoxazole (TMP-SMX):
Rifampin (particularly effective for hepatosplenic cat scratch disease):
- 20 mg/kg/day divided every 12 hours for 14 days 3
Clinical Considerations
Disease Characteristics
Cat scratch disease is caused by Bartonella henselae and typically presents with:
- Regional lymphadenopathy that develops about 3 weeks after inoculation
- A papule or pustule at the site of scratch/bite (3-30 days after exposure)
- Lymphadenopathy generally resolves within 1-6 months
- Suppuration occurs in approximately 10% of cases
- Extranodal disease (CNS, liver, spleen, bone, lung) develops in ≤2% of cases 1
Treatment Efficacy
- In a controlled study, azithromycin showed significant improvement with lymph node regression by 80% at 30 days compared to placebo (p=0.02) 1
- TMP/SMX has shown comparable effectiveness to azithromycin (61.5% vs 51.4% resolution/improvement) in pediatric patients 2
Special Situations
- Hepatosplenic involvement: Consider rifampin therapy (20 mg/kg/day divided every 12 hours). Patients typically improve within 1-5 days (mean 2.6 days) after starting rifampin 3
- Severe systemic disease: Consider gentamicin for patients with extensive systemic involvement 4
Important Considerations
Dosing Principles
- Always base antibiotic dosing on body weight rather than age for more accurate dosing 5
- Include the following on prescriptions: daily dose, number of divided doses, duration of therapy, indication, and child's weight 5
Treatment Duration
- Standard course for uncomplicated cat scratch disease: 5 days of azithromycin
- For complicated infections (hepatosplenic involvement): 14 days of therapy 3
Monitoring
- Most cases resolve without complications
- Monitor for extranodal manifestations, especially in immunocompromised patients
- Avoid incision and drainage of affected lymph nodes 6
Cat scratch disease is generally self-limited, but appropriate antibiotic therapy can shorten the course of illness and reduce complications, particularly in cases with systemic involvement or prolonged symptoms.