Hyperresponsiveness of congestive nasal reflexes in allergic rhinitis

Nasal secretory hyperresponsiveness is well documented in allergic rhinitis, and is mediated in part by neural mechanisms. In contrast, reflex-mediated congestion is poorly documented in both normal and allergic subjects.

To characterize congestive responses to unilateral nasal bradykinin challenge in normal and allergic subjects, and to investigate whether congestive hyperresponsiveness is present in allergic rhinitis.

Normal subjects (n = 13), and subjects with out-of-season seasonal allergic rhinitis (SAR) (n = 16) underwent a unilateral nasal challenge protocol using filter paper disks, using Hartman's solution and bradykinin as challenge substances. Congestive responses were measured using acoustic rhinometry.

Normal subjects demonstrated a transient ipsilateral congestive response, and a circumscribed contralateral congestive response away from the major flow limiting section. Subjects with SAR demonstrated a more persistent ipsilateral congestive response, and a more pronounced, generalized contralateral congestive response affecting all areas of the contralateral nasal cavity. Significant differences were present between normal and SAR subjects.

Congestive reflexes are present in normal and allergic subjects. Congestive hyperresponsiveness is present in allergic rhinitis.