Roughly 10% of patients report a penicillin allergy, making it the most common drug allergy noted in medical records. Yet when these patients are formally evaluated, more than 90% can tolerate penicillin without any reaction.
The label is not harmless. Patients carrying it are more likely to receive broader-spectrum alternatives such as fluoroquinolones and vancomycin, which are associated with more Clostridioides difficile infection, more resistance, and higher costs.
Many labels reflect a childhood rash, a family history, or a side effect that was never a true allergy. Structured evaluation — a careful history, and where appropriate skin testing or a supervised oral challenge — can safely remove the label in most cases.
Delabeling is one of the highest-yield stewardship interventions available, and it is increasingly something pharmacy and ID teams can drive together.