Anaphylaxis due to proton pump inhibitors: current understanding and important clinical considerations

Hypersensitivity reactions to proton pump inhibitors. An EAACI position paper

Proton pump inhibitors (PPIs) are invaluable therapeutic options in a variety of dyspeptic diseases. In addition to their well-known risk profile, PPI consumption is related to food and environmental allergies, dysbiosis, osteoporosis, as well as immediate and delayed hypersensitivity reactions (HSRs). The latter, although a rare event, around 1%-3%, due to the extraordinarily high rate of prescription and consumption of PPIs are related to a substantial risk. In this Position Paper, we provide clinicians with practical evidence-based recommendations for the diagnosis and management of HSRs to PPIs. Furthermore, the unmet needs proposed in the document aim to stimulate more in-depth investigations in the topic.

Comparison of recent anaphylaxis diagnostic criteria in real life: Can more patients be diagnosed as having anaphylaxis?

Introduction

In 2020, World Allergy Organization (WAO) updated their diagnostic criteria for anaphylaxis, which differed as a result from the National Institute of Allergy and Infectious Diseases/Food Allergy and Anaphylaxis Network (NIAID/FAAN) criteria which were still used in the 2021 update of the European Academy of Allergy and Clinical Immunology (EAACI) anaphylaxis guideline. Our aim was to evaluate and to compare both diagnostic criteria and attempt to identify factors affecting severity of anaphylaxis.

Methods

The medical records of the patients who were evaluated with suspected anaphylaxis at 3 medical centers in Türkiye between 2014 and 2021, and underwent a detailed diagnostic work-up, were analyzed retrospectively. Diagnosis of anaphylaxis was evaluated based on the WAO 2020 and EAACI 2021 and NIAID/FAAN diagnostic criteria. The severity of anaphylaxis was determined according to the WAO systemic allergic reaction grading system. Grade 5 anaphylaxis was defined as having respiratory failure, collapse/hypotension, loss of consciousness. Patients' demographic and clinical characteristics were further analyzed depending on the severity of the reaction.

Results

One thousand and six patients were evaluated and 232 patients without a convincing diagnosis of anaphylaxis were excluded from the study. The remaining 774 patients (70.6% female, median [Inter quartile range (IQR) 25-75] age: 42 [33-52]) were included for further examination. Anaphylaxis was diagnosed in 729 (94.2%) patients meeting both criteria whereas 35 patients (4.5%) with isolated laryngeal involvement and 10 (1.3%) patients with isolated respiratory involvement were only diagnosed according to the WAO 2020 criteria. Twenty-three patients (3.0%) had a diagnosis of indolent systemic mastocytosis. Mastocytosis was related to grade 5 anaphylaxis [p = 0.022, OR (CI) = 2.9 (1.1-7.6)]. Venom allergy was a risk factor for grade 5 anaphylaxis among those for whom an eliciting allergen could be determined [p = 0.03, OR (CI) = 2.7 (1.1-6.8)]. For drug induced anaphylaxis, parenteral route of drug administration and proton pump inhibitor (PPI) allergy were considered as risk factors for grade 5 anaphylaxis [p < 0.001, OR (CI) = 6.5 (2.5-17.0); p = 0.011, OR (CI) = 10.3 (1.6-63.3)].

Conclusion

This multicenter study demonstrated that both criteria identified the majority of patients with anaphylaxis, but the WAO 2020 diagnostic criteria identified an additional 6%. Hymenoptera stings, PPI allergy, parenteral drug administration, and underlying mastocytosis were associated with more severe episodes.

Beyond the Usual: Pantoprazole-Induced Anaphylaxis During Peribulbar Anesthesia

Proton-pump inhibitors (PPIs) are one of the most prescribed drugs in the world. Although they are remarkably safe, with minimal adverse effects, it has rarely been reported as a cause of anaphylaxis. Hence, we report the case of a 69-year-old patient who experienced intravenous pantoprazole-induced anaphylaxis during peribulbar block anesthesia for mechanical vitrectomy.