Utility of opium seed extract tests in preventing hypersensitivity reactions during surgery.

BACKGROUND: Anaphylaxis during anaesthesia is fatal in 3-9% of patients and analgesics, including opioids, and is the second most common medicament-related cause, although the prevalence is underestimated. We recently found that patients may generate IgE antibodies to opium seeds. OBJECTIVES: To determine the diagnostic accuracy of specific antibodies to morphine, codeine, rocuronium and oil body and aqueous fractions of Papaver somniferum seeds in the diagnosis and prevention of allergy to opioids. METHODS: Patients with hypersensitivity reactions during surgery, and severe clinical allergy (pollen, tobacco), and illicit heroin users were selected. The sensitivity, specificity and predictive values of in vivo and in vitro diagnostic techniques including oil body and aqueous fractions of P. somniferum seeds were measured. RESULTS: We studied 203 patients, with mean age 35.1±17.1 and 200 healthy controls. Patients sensitised to heroin or with hypersensitivity reactions during surgery responded to P. somniferum seed tests. Of patients not known to be sensitised to opioids, the highest positivity was in patients sensitised to tobacco (p<0.001). Opium seed skin tests and IgE, especially the oil body fraction, were more sensitive (64.2%) and specific (98.4%) than morphine, codeine and rocuronium tests for opioid sensitivity. Pollen allergy was not a risk factor for sensitisation to morphine. CONCLUSIONS: Sensitivity to opioids and intraoperative anaphylaxis can be diagnosed by routine tests. IgE and skin tests for the oil body fraction of P. somniferum had the highest sensitivity for sensitisation to opioids.

Opiate-sensitivity: clinical characteristics and the role of skin prick testing.

BACKGROUND: The value of skin prick testing in opiate-sensitive individuals is uncertain as opiates cause non-specific weals by direct degranulation of mast cells. OBJECTIVE: To define whether skin prick test (SPT) responses to opiates in opiate-sensitive individuals are different to those seen in the normal population and to describe the clinical characteristics of this group of subjects. METHODS: The SPT responses of eight opiate-sensitive subjects to morphine 10 mg/mL, pethidine (meperidine) 50 mg/mL and papaveretum 15.4 mg/mL at four different concentrations (undiluted, 1/10, 1/50 and 1/100) were compared with the responses of 100 (32 atopic) non-opiate-sensitive control subjects. Four of the opiate-sensitive subjects had a clinical history of asthma, rhinitis or urticaria on occupational exposure to morphine. One subject developed urticaria with codeine, one developed urticaria and asthma with morphine and diamorphine and two subjects reacted to intravenous papaveretum with anaphylaxis or urticaria. Five out of the eight cases had opiate sensitivity confirmed by single-blind placebo-controlled oral challenge. RESULTS: Skin prick tests to all three opiates were not significantly different when the eight opiate-sensitive subjects were compared with either the entire normal control group or the subgroup of 47 definite opiate-tolerant controls that had previously received opiates for clinical indications. Furthermore, there were no significant differences in size of opiate SPT responses between atopic and non-atopic control subjects. In the control subjects, there was a positive correlation in SPT weal size between the three opiates. CONCLUSION: Skin prick testing is not useful in the diagnosis of opiate sensitivity and placebo-controlled challenge should be considered.