The effect of histamine challenge on nasal airflow sensation

Objective nasal airflow resistance, as measured by the rhinomanometer, and the subjective sensation of nasal patency are usually regarded as showing poor correlation. However, previous population studies comparing nasal resistance and subjective nasal airflow sensation have failed to take into account the great individual variation in resting nasal resistance. To investigate the potential relationship between the two parameters, 20 healthy volunteers underwent histamine nasal challenge tests. Nasal resistance prior to the intra-nasal administration of histamine ('resting' nasal resistance, NRR) was compared with nasal resistance when the subject reported a subjective sensation of nasal blockage ('obstructed' nasal resistance, NR0) and the two were found to be significantly correlated using the Spearman rank correlation method (rs = 0.648, P = 0.002). Linear regression analysis using the method of least squares demonstrated an association between the two variables (P = 0.029), conforming to the formula NR0 = 1.26NR+0.478, (resistance units kPa.s.l-1). Subjective and objective measurements of nasal patency may be much more closely related than has previously been reported.