Approximately 10% of all U.S. patients carry a penicillin allergy label. The majority pick up the label in childhood after an adverse reaction or because a family member is labeled allergic. But the reality is that fewer than 1% of these patients have true immunoglobulin E-mediated sensitivity to the antibiotic, according to data cited by the CDC. And even the true penicillin allergies are often outgrown (JAMA 2017;318[1]:82-83).
This leaves a significant population of children