Eustachian tube function associated with histamine-induced and ragweed-induced rhinitis.

Nasal allergies may contribute to Eustachian tube dysfunction and chronic middle ear problems. In exploring this association further, Eustachian tube function was measured in ten ragweed-allergic and eight non-allergic patients undergoing repetitive nasal provocation. Anterior nasal provocation was done using paper disks impregnated with either histamine or aqueous ragweed allergen. Increasing concentrations of the provocative agent were placed on both inferior nasal turbinates until moderate symptoms of rhinitis developed. Eustachian tube function was evaluated using the 9-step inflation-deflation tympanometric test before and immediately after each nasal challenge. Eustachian obstruction developed in 4 of 38 non-allergic ears during histamine nasal provocation. With ragweed nasal challenge, 9 of 42 allergic ears developed Eustachian tube obstruction. Four allergic ears gained Eustachian tube function despite being obstructed before the challenge. The observed changes in ear function for both groups were not significant due to variability in Eustachian response. At the concentrations which initiated symptoms of rhinitis, nasal provocation with histamine or ragweed did not consistently obstruct the Eustachian tube. We conclude that mild symptoms of allergic rhinitis may not cause significant Eustachian tube obstruction.