Penicillin allergy associated with worse COVID-19 outcomes

Editor's Note

This study by researchers at the Pennsylvania State University College of Medicine, Hershey, finds that patients who had a penicillin allergy carried a higher risk for negative outcomes with COVID-19 than those without the allergy.

This analysis included 13,183 adults with COVID-19 and a penicillin allergy and 13,183 adults with COVID-19 and without a penicillin allergy.

Compared to those without a penicillin allergy, those with a penicillin allergy had a higher:

• 30-day hospitalization risk (34.8% vs 23.8%)
• need for intensive care (5.23% vs 4.35%)
• acute respiratory failure risk (21.8% vs 17.5%)
• need for mechanical ventilation (4.11% vs 3.53%).

There was a slightly higher mortality risk in penicillin-allergic patients during a 30-day observation period, but it was not statistically significant (4.06% vs 3.73%).

The basis for this negative effect of penicillin allergy on COVID-19 outcomes is unclear, however, it does not appear to be explained just by concurrent bacteremia and bacterial pneumonia because the higher risks persisted after patients with bacterial infection were excluded, the authors say. Based on the findings, COVID-19 patients with penicillin allergies could be prioritized to a higher risk group, they say.