Algorithms for the classification of patients with a β-lactam allergy label: a systematic review

Beta-lactam allergy is frequently reported, but only a minority of cases correspond to true allergies. Tools to stratify the risk of a real allergic reaction can possibly help delabeling patients. We aimed to retrieve evidence on algorithms for risk stratification of patients with a beta-lactam allergy label.

We performed a systematic review, searching three databases and included 28 studies. Most of the applied tools involved the assessment of the presence of rash/hives/other exanthemas ( n  = 24), angioedema/localized swelling ( n  = 23), bronchospasm/wheezing/dyspnea ( n  = 22) and gastrointestinal symptoms ( n  = 21). Seventeen studies classified participants into different categories according to their risk of having a penicillin allergy; three studies presented algorithms indicating management approaches to be followed; six studies applied predictive models. Most studies had a high risk of bias, particularly concerning the reference standard and lack of external validation.

Existing algorithms for beta-lactam allergy risk stratification are very heterogeneous and most of them lack validation.