A standardized filter paper technique for assessing nasal secretory activity.

A simple filter paper technique for estimating nasal secretory activity (NSA) was studied in 179 healthy adults. The technique was reproducible and NSA correlated independently with age and race (P less than 0.001 in each case) but not with sex or smoking habits. Subjects with a past history of atopic disease (asthma, rhinitis or eczema) produced significantly more nasal secretion than those without such a history (P less than 0.03). Among the former there was no significant difference in quantity of secretion recovered between those with and those without a past history of rhinitis. Increased NSA appears to be a marker of the atopic state and its measurement could be of value in the management of patients with allergic nasal disorders.