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

INTRODUCTION: Proton pump inhibitors (PPIs) are one of the most prescribed drug classes. PPIs are remarkably safe, with minimal side effects, most of which are related to drug's pharmacokinetic interaction profiles. However, hypersensitivity reactions can occur and anaphylactic reactions to PPIs have been described. Areas covered: A literature search in PubMed was performed to review the evaluation and management of anaphylaxis to PPIs. Clinicians should have a high level of suspicion and a drug allergy workup should be carried out by allergists, in a proper facility. Skin tests with PPIs are the only accurate methods to identify the culprit drug; they are also quite specific to solve cross-reactivity problems among drugs of this group. Expert commentary: A label of hypersensitivity to the whole group is generally not correct and tolerance to PPI with negative skin tests should be established with a negative oral challenge test. When an alternative drug among the whole group cannot be found, anti-H2 can be prescribed or a PPI desensitization protocol can be applied.

Hypersensitivity Reactions to Nonsteroidal Anti-Inflammatory Drugs among Adults: Clinical Features and Risk Factors for Diagnosis Confirmation.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDS) are among the most common causes of drug hypersensitivity (HS) reactions. The diagnosis is based on a careful clinical history, and provocation tests are considered the gold standard for diagnosis. Skin tests have some value to study reactions to pyrazolones. Laboratory investigations are mostly used for research purposes. Different phenotypes have been described. OBJECTIVE AND METHODS: Our aim was to describe the most common clinical manifestations of NSAID HS in a large population of adult patients, the drugs involved, the association with previously described risk factors, and the outcome of diagnostic procedures. The classification of reactions proposed by the European Academy of Allergy and Clinical Immunology (EAACI) Drug Allergy Interest Group was adopted. RESULTS: Acetylsalicylic acid was the drug most often involved in reactions (34%), isolated cutaneous symptoms were the most reported (60%), and immediate reactions (58%) were the most common. There was an overall female predominance (64%) and 35% of the patients were atopic. HS to NSAIDs was confirmed in 21% of the patients. The most common phenotypes encountered among HS patients were NSAID-induced urticaria/angioedema and single-NSAID-induced urticaria/angioedema or anaphylaxis. Logistic regression analysis showed that gender and atopy were not significant risk factors for HS confirmation, but diagnosis depended on the number of previous reactions, the type of reaction, and the time interval between drug intake and reaction. CONCLUSION: Only 21% of suspected HS reactions were confirmed after diagnostic workup. Patients describing >1 previous reaction and suffering immediate reactions had a higher probability of a positive investigation.