The nasal response to axillary pressure.

The changes in ipsilateral sympathetic tone in response to axillary pressure are well known. However, the response of the nasal mucosa is less well documented. We have attempted to demonstrate this response in normal individuals. Ten individuals with no history of nasal disease or allergy were studied. All subjects were exposed to sustained pressure, using a crutch, for a period of 5 min. Nasal cross-sectional area was measured on both sides of the nose using an acoustic rhinometer along with pulse and blood pressure. The individuals were then rested for at least 30 min and the test repeated with pressure applied to the opposite side. Statistical analysis was performed by non-parametric methods. There was a significant fall in nasal cross-sectional area on the side of pressure (median change = 0.09 cm2, P < 0.01) while cross-sectional area in the contralateral nasal passage increased (median change = 0.35 cm2, P = 0.01). There were no significant differences between these results and those obtained by axillary pressure on the opposite side. Pulse and diastolic blood pressure rose with axillary pressure while systolic blood pressure remained unaltered. There was no difference in the laterality in the blood pressure response. The results indicate that axillary pressure produces nasal congestion and both afferent and efferent arms of this reflex are side-specific.