Quantitative bronchial challenge tests with wheat flour dust administered by Spinhaler: Comparison with aqueous wheat flour extract inhalation

Bronchial challenge with flour: early response is dependent on the dose of activated allergen inhaled

“…However, the expression and interpretation of their results are not as well defined as for the methacholine test [4]. The authors have demonstrated that both PD f 20 and PD f 15 can be used to express the result and to compare with the lactose control test [3]. Nevertheless, the most appropriate inhaled dose must be determined for dose/ response curves to be established.…”

“…Firstly, Qc was used from the beginning of the challenge to determine PD f 15 and PD f 20. This method was suitable for patients with high hyperreactivity, because the initial periods of exposure were short and each additional dose caused an additional effect [3].…”

“…The methods of specific challenge differ in the nature and the physical state of the allergens (gas, dry aerosol, aqueous extract), in the delivery procedure, and in the protocol for increasing the dose. There are two major types of protocol for determining dose/response relationships: 1) increasing the time of exposure at controlled concentration with closed-circuit devices [1][2][3]9]; and 2) geometrically increasing the concentration or the dose of the allergen nebulised from a dosimeter and inhaled for 1-5 breaths [6,14,15].…”

Allergic asthma after flour inhalation in subjects without occupational exposure to flours: an experimental pilot study

“…Beyond the description of these diVerences, we are unable to give an explanation for the isolated late reaction, but we consider an irritant reaction unlikely. Also, previous studies demonstrated that irritant reactions following high concentrations of Xour inhalations do not occur in asthmatics without Xour sensitization (Merget et al 1997).…”

“…Sensitization to Xours at baseline did not predict allergic symptoms in Wrst-year apprentices (Herxheimer 1967), and baseline SPT reactions to Xours could not be reproduced in a substantial number of apprentices in follow-up examinations (Herxheimer 1973). Additionally, inhalation studies performed with high doses of Xours in control subjects with positive SPT reactions to Xour were negative (Merget et al 1997). However, this study was performed only in two subjects.…”