Penicillin allergy: a practical approach to assessment and prescribing

Penicillin allergies are not always lifelong. Approximately 50% are lost over five years. A reaction to penicillin during a childhood infection is unlikely to be a true allergy. Only 1-2% of patients with a confirmed penicillin allergy have an allergy to cephalosporins. In patients with a low risk of severe allergic reactions, cephalosporins are a relatively safe treatment option. Patients with a history of delayed non-severe reactions, such as mild childhood rashes that occurred over 10 years ago, may be suitable for an oral rechallenge with low-dose penicillin. This should be done in a supervised hospital environment. In many cases, with appropriate assessment and allergy testing, it may be possible to remove the penicillin allergy label.