Clinical Manifestations and Diagnostic Evaluation of Opioid Allergy Labels - A Review.

While opioids represent one of the most common medication allergy labels, these labels are often unsubstantiated in clinical practice. The removal of erroneous opioid allergy labels has a unique importance in the population with acute or chronic pain. The current approach to patients with pseudo-allergy to opioids is switching to an alternative opioid with less histamine release. Thus, allergy labels to relatively lower potency opioids such as codeine may be feasibly result in the prescription of stronger medications like fentanyl that would otherwise not be indicated. This narrative review provides an overview of the epidemiology and clinical manifestations of opioid allergy labels commonly encountered by pain management practitioners along with recommendations for evaluation and management. A literature search of PubMed was performed using the comprehensive MeSH term, "Opioid Allergy". In recent years, it has become apparent that a substantial proportion of patients labeled as opioid allergic are found to be tolerant of these agents. Opioid skin testing and IgE assays are of limited application. DPT is the yet underutilized gold standard for diagnosis. There is also an increasing call for studies evaluating basophil activation testing in opiate allergy. Opioid allergy labels require a closer look especially in view of the current opioid epidemic. The low likelihood of true reactivity, combined with the conceivable clinical relevance of an opioid allergy label, calls for further characterization of this label in populations with acute or chronic pain diagnoses. Future directions should include larger prospective studies with systematic evaluation and classification of opioid allergy labels to determine future viability of opioid use. Abbreviations EHR electronic health record NMBA neuromuscular blocking agent IgE immunoglobulin E MC mast cell GPCR G-protein coupled receptor MRGPRX2 mas-related G-protein receptor QAI quaternary ammonium ions SCAR severe cutaneous adverse reaction AGEP acute generalized exanthematous pustulosis SDRIFE symmetrical drug-related intertriginous and flexural exanthema BAT basophil activation testing DPT drug provocation testing.