Penicillin is the most common drug allergy identified in EMR
10 % of US population (33 million persons) have a documented Penicillin allergy (1)
True IgE – Mediated (Immediate, type I) allergies that cause anaphylaxis are uncommon
Prevalence of life-threatening anaphylactic reactions to penicillin estimated to be between 0.02% and 0.04% - the most common reaction is a cutaneous eruption
More than 95 % of patients labeled as Penicillin allergic tolerate this class of drugs
Most Penicillin allergies are acquired in childhood (75% of Penicillin allergy labels are obtained by the age of 3 years)
Why are > 95% of Penicillin allergic patients PCN tolerant?
Most commonly reported Penicillin hypersensitivity reaction is a delayed, benign rash
IgE – Mediated Penicillin allergy wanes over time
80% of patients become tolerant after 10 years (2)
Many patients never were allergic ( drug intolerance or other cause)
