Probability and pragmatism in penicillin allergy evaluations.

摘要

A recent Annals review stated that the negative predictive value (NPV) of skin testing for identifying patients with immediate penicillin hypersensitivity was 97% to 99%. The NPV is important because physicians must weigh the possibility of a serious allergic reaction, such as an alternative drug's adverse effects and resistance development, against the consequences of not using a beta-lactam. A decision analysis model argued for switching to an alternative antibiotic when there is a 1:100 chance of a severe allergic reaction without performing skin testing to confirm or deny sensitivity because the results of skin testing would not change therapy given the thresholds obtained from a number of clinicians. An example was submitted: a syphilis patient who 5 years earlier had urticaria on the third day of ampicillin treatment would be offered only alternative antibiotic treatment (tetracycline) instead of penicillin testing.