Standardized Allergen Provocation Test

Standardized bronchial allergen provocation with the same individual allergen dose was performed 3–9 times in 20 symptomless adult asthmatic patients at intervals of 1 week or more during 1/222 months in order to study variations in bronchial response. The immediate type reaction was recorded by monitoring FEV₁, FVC, PEFR and MEF_50% for 30–40 min after provocation. FEV₁ was highly significantly correlated to the other variables.
The coefficient of variation corresponding to maximum decrease in FEV, was 23%. All provocations were followed by a bronchial reaction within clinically acceptable limits. There was no indication of hypo- or hypersensitization.
It is concluded that although many different factors influence the bronchial response, careful standardization of the provocation procedure leads to a moderate variation in bronchia! response, making the allergen provocation test suitable for pathophysiological studies and clinical evaluation of anti–asthmatic drugs.