[Bronchopneumopathy caused by wheat flour: analysis of clinical cases].

We studied 31 subjects exposed to wheat (mean work duration: 33 years) with chronic bronchopulmonary disease. 19 subjects complained of chronic cough and phlegm, 5 of symptoms of bronchoconstriction not associated to chronic cough and phlegm; 7 subjects complained of oculo-rhinitis. Subjects with symptoms of bronchoconstriction had a longer mean age and work duration than the other ones. Pulmonary function tests showed a slight decrease of mid-expiratory flow rate with respect to reference values. Skin reactivity to common allergens and to allergenic extracts of wheat flour and grain was low, but a relevant number of dubious responses (weal: 3-4 mm) to specific allergens was observed. Bronchial hyperresponsiveness to methacholine or bethanechol was observed in 17 out of 30 subjects, and a positive response to occupational-type specific bronchial provocative test (sBPT) was elicited in 10 out of 30 subjects. There was a low relationship between positive response to sBPT and symptoms of bronchoconstriction or skin reactivity to specific allergens. These observations suggest that a high prevalence of chronic bronchitis and/or chronic airway limitation is showed in workers long-term exposed to wheat flour, in front of a low prevalence of skin reactivity to flour and grain. Occupational-type sBPT might induce in these patients a non immunological positive response to wheat flour by means of a not completely known mechanism.