Quantification of the dose of inhaled flour: relation with nonspecific bronchial and immunological reactivities

The aim of this study was to investigate the relationship between specific bronchial reactivity and respective nonspecific bronchial and immunological reactivities. Twenty-one patients underwent bronchial challenges with lactose and flour. The aerosol of particles was generated by a computer-controlled aerosolizer. Specific bronchial challenge results were expressed as the provocative dose of flour (PDf) that caused a 20% or 15% decrease in the forced expiratory volume in one second (FEV1). For each subject, the decrease in FEV1 observed during the challenge with flour was compared with the calculated lower limit of the 99.7% confidence interval for the lactose challenge. The subjects also underwent a nonspecific challenge with methacholine and a measurement of the specific immunoglobulin E against wheat. The inhalation of lactose did not significantly affect FEV1. Nine subjects had high reactivity to wheat flour with a PDf20