Simplified spinhaler method for antigen-specific bronchoprovocation in children with bronchial asthma. I

Specific bronchial challenge has been performed using a micronized, freeze-dried allergen extract of D. pteronyssinus administered as a powder at increasing concentrations (0, 50, 100, 200, 400, 600, 800, and 1,000 Allergenic Units) by a cromolyn spinhaler delivery system. The test was performed in ten asthmatic children with house mite D. pteronyssinus skin test and RAST positivity and in six non-allergic asthmatic children. A positive early reaction to bronchial challenge occurred in eight out of ten allergic children. A ninth child of this allergic group presented only the late reaction. Five patients of the control group (skin test and RAST negative for D. pteronyssinus had negative results while one child had a positive response both with early and late reactions. A significant increase in methacholine sensitivity was observed in the allergic group the day following the specific challenge. The modified spinhaler procedure (Hypoinhal, Lofarma) used for specific bronchial challenge showed a good correlation with skin test and RAST positivity in patients as well as in the control population. The method provides advantages of simplicity, ease of performance and cost effectiveness.