Opioid Hypersensitivity: Predictors of Allergy and Role of Drug Provocation Testing.

True IgE-mediated hypersensitivity to opioids is rare and many reactions are due to direct mast cell degranulation. Opioid drug provocation testing (DPT) is the gold standard for diagnosis but is underutilized. The objective of this study was to evaluate the clinical characteristics and predictors of opioid hypersensitivity, as well as outcomes of opioid DPT. Patients referred for opioid DPT over the past 9 years were studied. Patient characteristics, indications for opioid use, symptoms of index reaction, and outcomes of DPT were analyzed. Association analysis was performed to study variables associated with a diagnosis of opioid hypersensitivity. Of the total of 98 patients referred with suspected opioid hypersensitivity, 15 (15%) were diagnosed with opioid allergy. Angioedema (odds ratio [OR]: 5.66; 95% confidence interval [CI]: 1.49-21.47; P = .011) and hypotension (OR: 5.00; 95% CI: 1.15-21.70; P = .032) were significantly more frequent in opioid allergic patients than those with a negative DPT. Patients who received opioids during anesthesia were significantly more likely to be opioid allergic (OR: 6.74; 95% CI: 2.05-22.13; P = .001). In contrast, a negative association was identified with patients who received opioids for analgesia (OR: 0.27; 95% CI: 0.08-0.86; P = .008). Only 15% of our cohort were diagnosed with opioid allergy, emphasizing the importance of DPT in preventing erroneous overdiagnosis. Patients with a history of angioedema or hypotension as their index reaction were significantly more likely to be opioid allergic. DPT are safe when performed by experienced clinicians after risk stratification and using individualized protocols.