Prevalence of IgE against neuromuscular blocking agents in hairdressers and bakers

BackgroundAllergic IgE-mediated reactions to neuromuscular blocking agents (NMBAs) are the main cause of immediate hypersensitivity reactions in anaesthesia; their predominant occurrence in the absence of previous exposure to NMBAs suggests a risk related to environmental exposure. ObjectiveTo investigate the prevalence of specific IgE to quaternary ammonium ions in two populations professionally exposed to quaternary ammonium compounds, in the north-eastern France. MethodsThe study had a retrospective follow-up design whereby apprentices were assessed after their 2-year training period as apprentices. The professionally exposed hairdresser populations (n=128) were compared with baker/pastry makers (n=108) and non-exposed' matched control subjects (n=379). ResultsWe observed a 4.6-fold higher frequency of positive IgE against quaternary ammonium ions in hairdressers (HD), compared with baker/pastry makers (BP) and control (C) groups. The competitive inhibition of quaternary ammonium Sepharose radioimmunoassay (QAS-IgE RIA) with succinylcholine was significantly higher in HD, compared with BP and C groups, with inhibition percentage of 66.27.4, 39.7 +/- 6.0 and 43.8 +/- 9.9, respectively (P<0.001). The specific IgE against quaternary ammonium ions recognized also two compounds widely used by hairdressers, benzalkonium chloride and polyquaternium-10, in competitive inhibition of IgE RIA. When considering the whole study population, hairdresser professional exposure and total IgE>100kU/L were the two significant predictors of IgE-sensitization against quaternary ammonium ions in the multivariate analysis of a model that included age, sex, professional exposure, increased concentration of total IgE (IgE>100kU/L) and positive IgE against prevalent allergens (Phadiatop((R)); P=0.019 and P=0.001, respectively). Conclusion and Clinical RelevanceThe exposure to hairdressing professional occupational factors increases IgE-sensitization to NMBAs and quaternary ammonium ion compounds used in hairdressing. Besides the pholcodine hypothesis, our study suggests that repetitive exposure to quaternary ammonium compounds used in hairdressing is a risk factor for NMBAs sensitization.