Metalworking fluids: a new cause of occupational non-asthmatic eosinophilic bronchitis

In addition to bioaerosols, previous challenge studies have established chemical constituents of MWFs including ethanolamine and biocides to be causes of OA. 2 Metals dissolved in MWFs have also been reported to cause asthma, but none used in this case were known causes. [...]although exact mechanisms are not fully understood, inhalation of both chemical and biological allergens in MWF mist is thought to cause OA in susceptible workers. The condition has been reported to have been caused by a small number of occupational agents also recognised to cause OA including acrylates, isocyanates, flour, [alpha] amylase, chloramine, styrene, formaldehyde, latex and stainless steel welding. 3 Since a number of agents present in MWFs can cause OA, it is plausible that they cause NAEB. Evidence from the few follow-up studies in non-occupational NAEB suggests that over two-thirds of affected individuals continue to be symptomatic 1 year after diagnosis, with around 10% going on to develop more classical features of asthma. 5 For this patient, removal from exposures would be ideal to present the best outcome for symptom control.