Frequency of self-reported drug allergy A systematic review and meta-analysis with meta-regression

Background: Patients reporting drug allergy are treated with second-line therapies, with possible negative clinical and health consequences. Objective: To assess the prevalence of self-reported drug allergy. Methods: We performed a systematic review of observational studies assessing the prevalence of self-reported drug allergy. We searched 4 electronic databases. From selected studies, we extracted data on self-reported drug allergy prevalence, study design, participants' demographic characteristics, reported clinical manifestations, and suspected culprit drugs. We performed a random-effects meta-analysis followed by a meta-regression. Results: Fifty-three studies were included in the systematic review, assessing a total of 126,306 participants, of whom 8.3% (range across studies 0.7-38.5%) self-reported drug allergy. Cutaneous manifestations were reported by 68.2% of participants, and anaphylactic or systemic reactions were reported by 10.8%. Antibiotics, nonsteroidal anti-inflammatory drugs, and anesthetics were the most frequently reported culprit drug classes. The frequency of self-reported drug allergy was higher in female (11.4%) than in male (7.2%) patients, adults (10.0%) than in children (5.1%), and in studies in the medical setting (15.9% in inpatients, 11.4% in outpatients) than in the general population (5.9%). The meta-analysis rendered a pooled prevalence of 7.9% (95% confidence interval 6.4-9.6), and the meta-regression identified study region, participants' age group, and study setting as factors associated with significant heterogeneity. Confirmation tests (including skin, in vitro, and drug provocation tests) were performed in only 3 studies. Conclusion: The prevalence of self-reported drug allergy is highly variable and is higher in female patients, adults, and inpatients. To overcome this variability, further studies using confirmation tests are needed. (C) 2017 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.