Recommended Antibiotic Syrup for Treating Impetigo
For treating impetigo in children, oral cephalexin syrup is the recommended first-line antibiotic when oral therapy is indicated, with alternatives including clindamycin or sulfamethoxazole-trimethoprim (SMX-TMP) when MRSA is suspected. 1
Types of Impetigo and Causative Organisms
- Impetigo presents in two forms: bullous and non-bullous. Bullous impetigo is exclusively caused by toxin-producing Staphylococcus aureus, while non-bullous impetigo can be caused by S. aureus, Streptococcus pyogenes, or both. 1, 2
- Non-bullous impetigo begins as erythematous papules that evolve into vesicles and pustules that rupture, forming honey-colored crusts on an erythematous base. 1
- Bullous impetigo presents with fragile, thin-roofed vesicopustules that may rupture, creating crusted erosions. 2
Treatment Algorithm for Impetigo
Topical vs. Oral Therapy Decision
- Limited lesions: Topical antibiotics (mupirocin or retapamulin) twice daily for 5 days are first-line therapy. 2, 3
- Oral antibiotics are indicated when: 1
- Patient has numerous or extensive lesions
- During outbreaks affecting multiple people
- When topical therapy fails after 3-5 days
- When systemic symptoms are present
First-line Oral Antibiotic Options (Syrup for Children)
- Cephalexin syrup: 25-50 mg/kg/day divided into 4 doses for 7 days (first-line for presumed methicillin-susceptible S. aureus) 1, 4
- Dicloxacillin syrup: 25-50 mg/kg/day divided into 4 doses for 7 days (alternative first-line) 1
Alternative Oral Antibiotics (When MRSA is Suspected)
- Clindamycin syrup: 20-30 mg/kg/day divided into 3 doses for 7 days 1, 4
- Sulfamethoxazole-trimethoprim (SMX-TMP) syrup: 8-12 mg/kg/day (based on trimethoprim component) divided into 2 doses for 7 days 1
- Doxycycline syrup: For children >8 years old, 2-4 mg/kg/day divided into 2 doses for 7 days 1, 4
Important Clinical Considerations
- Penicillin alone is not effective for impetigo since it lacks adequate coverage against S. aureus, which is present in most cases. 2, 5
- The duration of oral antibiotic therapy should be 7 days. 1, 4
- Topical antibiotics have been shown to have similar efficacy to oral antibiotics for limited disease and cause fewer side effects. 3, 5
- Oral antibiotics cause more side effects than topical treatments, particularly gastrointestinal effects. 3, 5
- In areas with high MRSA prevalence, empiric therapy should cover MRSA until culture results are available. 1, 4
- Systemic antimicrobials should be used during outbreaks of poststreptococcal glomerulonephritis to eliminate nephritogenic strains. 1
Special Populations and Precautions
- Avoid tetracyclines (doxycycline) in children under 8 years due to risk of dental staining. 4
- Consider cephalexin as a safe alternative for pregnant patients. 4
- For patients with penicillin allergy, clindamycin or macrolides can be used, though resistance rates to erythromycin are rising. 1, 6