Non-specific reactions caused by diluents containing glycerol in nasal and bronchial challenge tests

Sixty-one patients hospitalized because of asthma and/or allergic rhinitis were given nasal and bronchial challenge tests with diluents containing glycerol. 62% of the patients with rhinitis and 37% of those with asthma gave positive reactions. Glycerol should therefore not be used in allergen extracts which are meant for challenge tests. The non-specific effect of glycerol seems to be cumulative with increasing dose.