Treatment for Strep Pharyngitis in Patients with Penicillin Anaphylaxis
For patients with strep pharyngitis who have an anaphylactic reaction to penicillin, clindamycin (7 mg/kg/dose three times daily, maximum 300 mg/dose) for 10 days is the recommended first-line treatment. 1, 2, 3
First-Line Treatment Options
- Clindamycin is the preferred treatment for patients with anaphylactic sensitivity to penicillin, administered at 7 mg/kg/dose three times daily (maximum 300 mg/dose) for 10 days 1, 2, 3
- Clindamycin has demonstrated high efficacy in eradicating streptococci, even in chronic carriers 3
- Resistance to clindamycin among Group A Streptococcus isolates in the United States is low, approximately 1% 3
Alternative Treatment Options
- Clarithromycin is an alternative option, administered at 7.5 mg/kg/dose twice daily (maximum 250 mg/dose) for 10 days 1, 2
- Azithromycin can be used at 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 2
- Macrolides (azithromycin and clarithromycin) should be used with caution due to variable resistance rates that differ geographically 1, 2, 3
Important Considerations
- First-generation cephalosporins (cephalexin, cefadroxil) should be avoided in patients with anaphylactic reactions to penicillin due to potential cross-reactivity (up to 10%) 1, 3
- The full 10-day course of antibiotics (except for 5 days with azithromycin) is important to achieve maximal pharyngeal eradication of Group A Streptococcus 1, 4
- Local resistance patterns should be considered when prescribing macrolides, as resistance rates can vary significantly by region 2, 3, 5
Adjunctive Therapy
- Acetaminophen or NSAIDs can be used for symptomatic relief of moderate to severe symptoms or high fever 2, 3, 4
- Aspirin should be avoided in children due to the risk of Reye syndrome 1, 3
- Corticosteroids are not recommended as adjunctive therapy 1, 3
Follow-Up Recommendations
- Routine post-treatment throat cultures are not recommended for asymptomatic patients who have completed therapy 1, 3
- Patients with worsening symptoms after appropriate antibiotic initiation or with symptoms lasting 5 days after the start of treatment should be reevaluated 5
Common Pitfalls to Avoid
- Using first-generation cephalosporins in patients with anaphylactic reactions to penicillin due to potential cross-reactivity 1, 3
- Prescribing macrolides in areas with high resistance rates without considering local patterns 2, 3
- Treating viral pharyngitis with antibiotics (most cases of sore throat are viral) 4
- Unnecessary tonsillectomy solely to reduce frequency of GAS pharyngitis 1
Remember that while clindamycin is the preferred treatment for patients with anaphylactic penicillin allergy, the choice between clindamycin and macrolides should consider local resistance patterns, patient-specific factors, and medication side effect profiles.