Diagnosis of flour-induced occupational asthma in a cross-sectional study

AbstractThe diagnosis of occupational asthma is usually performed in epidemiology using a combination of symptoms and bronchial hyperresponsiveness, while in a clinical setting the ‘gold standard’ for the diagnosis of occupational asthma is the specific bronchial challenge test in the laboratory. The aim of this study was to detect new cases of flour-induced occupational asthma (OA) in a group of workers exposed to grain and/or flour dust, by means of a step-by-step approach, as used in a clinical setting. In an epidemiological study, 111 millers and 186 bakers were examined by means of questionnaire, pulmonary function tests and skin-prick tests (SPT) to common allergens and to wheat flour dust extracts. From the whole sample, 82 subjects who showed asthma-like symptoms in the questionnaire and/or low forced expiratory volume in 1 sec (FEV1) were selected. Selected subjects underwent methacholine challenge test, and hyperreactive subjects underwent specific bronchial challenge with flour dust in the laboratory. Sixty-two of the selected subjects performed the methacholine challenge test, and 22 (33·8%) were hyperreactive (PD20 FEV1