NASAL HISTAMINE CHALLENGE IN NONALLERGIC AND ALLERGIC SUBJECTS EVALUATED BY ACOUSTIC RHINOMETRY

Nasal patency shows spontaneous variations but is influenced by a numb er of factors like exercise and allergic conditions. Nasal histamine c hallenge has been used to define nasal hypersensitivity. We have appli ed acoustic rhinometry as a new objective method to study the spontane ous variations of the nasal mucosa and its response to histamine chall enge in 12 nonallergic subjects and 12 subjects with nasal allergy to pollen, but out of the pollen season. Measurements of the minimum cros s-sectional area and the volume of the nasal cavities were done every 15 min for 6 h. More pronounced spontaneous variations, defined by the coefficient of variation of the measurements, were encountered in the allergic than in the nonallergic subjects, especially with regard to the minimum cross-sectional areas in the nasal cavities (P < 0.02). Al lergic subjects showed increased sensitivity to histamine, as compared with nonallergic subjects, during low-concentration (0.1%) challenge (P < 0.05) and a prolonged effect of histamine challenge (P = 0.01). A ntihistamine (cetirizine) had a significant effect on the histamine-in duced symptoms and decrease of nasal dimensions during histamine chall enge, but no significant effect on pollen-induced changes. In the alle rgic group, the decrease in minimum area during allergen provocation c orrelated with the level of specific IgE (r = 0.81; P = 0.0015).