[Bronchial hyperreactivity to methacholine in a group of bakers sensitized to wheat flour]

Bakers' allergic diseases are a well known occurrence. Wheat flour is the most important allergen responsible for rhinoconjunctivitis and IgE mediated asthma. The good correlation between atopy, wheat flour sensitization and allergic diseases is also well known. In a previous study we described the results concerning sensitivity to wheat flour in a group of 300 bakers, followed up for 8 years. In this study we showed that the same subjects who were sensitive to wheat flour had no symptoms.

The aim of this study was to carry out the metacholine test for bronchial hyperreactivity in a group of 14 bakers selected from the group of 300 previously studied.

The subjects underwent: pulmonary function test, IgE test, skin prick test with grass pollen, Dermatophagoides farinae, Dermatophagoides pteronissinus, wheat flour, and the metacholine test.

The results of the metacholine test showed only one positive case in a subject with positive skin prick test. This agreed with the assumptions of our previous study that showed a sensitization (10%) to wheat flour but a low prevalence of allergic symptoms.

Limited to the subjects studied, the results indicate an absence of a relationship between positive prick tests and aspecific bronchial hyperreactivity. Recent research that suggest a probable different genetic control of atopy, bronchial hyperreactivity and asthma is discussed. In our opinion effective primary and secondary prevention could account for this absence of relationship.