Diagnosis of allergic drug reactions according to the medical history

Published Online: February 3, 2016

Allergic drug reactions (ADR), the third most common reason for consultation in allergy clinics, affect 10-20% of hospitalized patients and up to 7% of outpatients, although this  might be an underestimate due to underreporting, or an overestimate due to classification of unexplained reactions as "allergic". ADR may be a cause of severe morbidity and increased  costs resulting from increased use of emergency services and hospitalizations, and extended hospital stays. Quantification of the risk of an ADR through the medical history is, generally entirely subjective in usual clinical practice.

In this issue of The Journal of Allergy and Clinical Immunology: In Practice, Hierro et al. report on a 12 month study of 466 patients  with the objective of constructing a mathematical model to predict the risk of ADR using data from the medical history. Associations between variables from the medical history and the final diagnosis of ADR confirmed or ruled out were determined using binary logistic regression.

Variables predictive of a diagnosis of ADR were: age, sex, drug class, number of active principles, time to the reaction, number of doses, clinical presentation suggestive of allergic disease, and time to medical consultation. Of the 626 active principles evaluated, an ADR was ruled out in 58.1%, confirmed in 13.4%, remained as suspected in 26.4%, and confirmed as an idiosyncratic reaction in 2.1%. Our results suggest that an ADR could be predicted to be ruled out in up to 40% of active principles in the initial consultation using only data from the medical history.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

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