A comparison of the response to histamine challenge of the nose and the maxillary sinus: effect of loratadine. Baroody, Fuad M., M. D., Anil Gungor, M. D., Marcy Detineo, R. N., Lauran Haney, B. Sc., Christopher Blair, B. Sc., Robert M. Naclerio, M. D. From the Section of Otolaryngology-Head and Neck Surgery, Pritzker School of Medicine, The University of Chicago, Chicago, Illinois, 60637.
APStracts 6:0240A, 1999.
To study the response of the maxillary sinus to histamine provocation, we performed a double blind, randomized, cross-over trial during which nonallergic subjects without symptoms of rhinitis (n=25) received either 10 mg loratadine or placebo once daily for a week and then underwent nasal challenge with histamine (3, 10 and 30 mg/ml) followed, 24 hours later, by a maxillary sinus challenge while still receiving the medication. Nasal challenge with histamine led to significant increases in vascular permeability, reflex nasal secretions, sneezing and other nasal symptoms. Sinus challenge resulted in significant increases in vascular permeability within the sinus cavity (p<0.01) and some nasal symptoms but no significant change in reflex nasal secretions. The response of the sinus mucosa to histamine was lower in magnitude than that of the nose. Treatment with loratadine resulted in a significant inhibition of the histamine-induced changes in both nasal and sinus cavities. Our data suggest the lack of a sinonasal reflex response to histamine provocation of the maxillary sinus of nonallergic individuals. 

Received 14 December 1998; accepted in final form 20 May 1999.
APS Manuscript Number A1138-8.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1999 The American Physiological Society.
Published in APStracts on 14 June 1999