Effect of Penicillin Allergy Label on Antibiotic Treatment Outcomes in Adult Patients with Rhinosinusitis

Objective Rhinosinusitis (RS) is prevalent in the ambulatory setting. When indicated, treatment with penicillin is recommended. However, up to 25% of the US population has a penicillin allergy label (PAL) within their health record, which can result in treatment with second‐line antibiotics. The study explored the effect of PAL on clinical outcomes in RS. Study Design Retrospective chart review. Setting Ochsner Medical Centre. Methods A chart review was performed in adult patients with RS who received antibiotics between 2011 and 2024. Treatment failure was defined as need for a second antibiotic within 30 days. Adverse events (AE) were indexed to a new diagnosis of diarrhea within 30 days. Odds ratio (OR) of success:AE was calculated and compared to standard of care, using Cohen's h to measure the effect size of nonpenicillin antibiotics. Results 335,015 subjects who received antibiotics for RS were included. Of these, 55,557 (16.6%) had PAL. These patients were more likely to receive a nonpenicillin antibiotic for initial therapy (87.8%). Patients with a PAL had a slightly greater rate of treatment success (78.2% vs 75.8%, h = 0.057), but a greater AE rate (1.8% vs 1.7%, h ‐0.015). Among second‐line treatments for patients with PAL, tetracycline had a superior OR of success: AE (0.983, 95% CI 0.906‐0.894) compared to fluoroquinolones (0.842, 95% CI 0.843‐0.831). Conclusion In patients with RS, PAL often leads to the prescription of a second‐line antibiotic, which has decreased benefit‐to‐risk ratio compared to first‐line treatment. This emphasizes the need for additional efforts to remove PALs from patients without true penicillin allergy.