The nasal response to isometric exercise in non-eosinophilic intrinsic rhinitis.

The exact pathophysiology of intrinsic rhinitis is not fully understood. The generally held belief is that it is due to an imbalance between the outflow of the nasal sympathetic and parasympathetic nervous systems, perhaps due to excessive parasympathetic or reduced sympathetic activity. In this study the nasal airway response to a predominantly sympathetic stimulus, isometric exercise, was studied in 19 patients with intrinsic rhinitis and compared with 16 normal patients. Isometric exercise took the form of a handgrip stimulus using a hand dynomometer. Following sustained handgrip, a small fall of nasal resistance in the normal group (0.058 kPas/1) and a moderate rise in nasal resistance in the rhinitis group (0.242 kPas/1) was found. Pulse and blood pressure changes were the same in both groups with a significant rise in pulse rate and diastolic blood pressure. The study shows that there is an abnormal response to isometric exercise in intrinsic rhinitis, perhaps due to relative nasal sympathetic hyposensitivity.