What is the recommended treatment for impetigo in a patient with a cefdinir (Cefdinir) allergy?

Treatment of Impetigo in Patients with Cefdinir Allergy

For patients with a cefdinir allergy, the recommended treatment for impetigo is topical mupirocin or retapamulin for limited lesions, or oral clindamycin or sulfamethoxazole-trimethoprim (SMX-TMP) for extensive disease. 1, 2

First-Line Treatment Options

Limited Lesions

• Topical antibiotics are first-line therapy for limited impetigo lesions and are as effective as oral antibiotics 1, 2, 3
  • Mupirocin 2% ointment applied twice daily for 5 days 2
  • Retapamulin 1% ointment applied twice daily for 5 days 2

Extensive Disease or Multiple Lesions

• Oral antibiotics are recommended for extensive impetigo, multiple lesions, or outbreaks affecting several people 1, 2
  • Clindamycin (10-day course) is an excellent option for penicillin-allergic patients with only ~1% resistance among GAS isolates in the US 1
  • Sulfamethoxazole-trimethoprim (SMX-TMP) is effective, particularly when MRSA is suspected 1, 2
  • Doxycycline (for patients ≥8 years old) is another alternative 1

Treatment Considerations Based on Allergy Type

For Non-Anaphylactic Penicillin Allergy

• First-generation cephalosporins (e.g., cephalexin) may be used for 10 days if the patient doesn't have anaphylactic sensitivity to penicillin 1
• Recent data indicate cross-reactivity between penicillins and second/third-generation cephalosporins is lower than historically reported 4

For Anaphylactic Penicillin Allergy

• Avoid all beta-lactam antibiotics including cephalosporins 1
• Use clindamycin, macrolides (clarithromycin, azithromycin), or SMX-TMP 1, 2

Special Considerations

Type of Impetigo

• Bullous impetigo is caused exclusively by S. aureus 2
  • Requires coverage for S. aureus, with consideration for MRSA in areas with high prevalence 2
• Non-bullous impetigo can be caused by both S. aureus and Streptococcus pyogenes 1, 2
  • Requires broader coverage that addresses both pathogens 1

MRSA Considerations

• In areas with high MRSA prevalence, empiric therapy should include MRSA coverage until culture results are available 1, 2
• Clindamycin, SMX-TMP, or doxycycline are preferred options 1, 2

Duration of Therapy

• Topical antibiotics: 5 days 2, 3
• Oral antibiotics: 7-10 days 1
• Macrolides: clarithromycin for 10 days or azithromycin for 5 days 1

Common Pitfalls and Caveats

• Penicillin alone is not effective for bullous impetigo since it's caused exclusively by S. aureus 2
• Tetracyclines should not be used in children under 8 years due to dental staining 1
• Gastrointestinal side effects are more common with oral antibiotics compared to topical treatment 3
• Always consider local resistance patterns when selecting empiric therapy 1, 2
• Systemic antimicrobials should be used during outbreaks to eliminate transmission of infection 1, 2

Treatment Algorithm

1. Determine extent of impetigo (limited vs. extensive)
2. For limited disease: Use topical mupirocin or retapamulin 1, 2, 3
3. For extensive disease: Select oral antibiotic based on allergy profile 1
   • Non-anaphylactic penicillin allergy: Consider first-generation cephalosporins 1
   • Anaphylactic penicillin allergy: Use clindamycin, macrolides, or SMX-TMP 1
4. In areas with high MRSA prevalence: Include MRSA coverage (clindamycin, SMX-TMP, doxycycline) 1, 2