Nasal provocation with histamine: a comparison of the determination of the threshold of reactivity by three methods of rhinomanometry.

Three methods of rhinomanometry were compared with each other with respect to their ability to determine the histamine threshold (histamine concentration for a 100% increase of the initial total nasal resistance): the active anterior rhinomanometry (P.A.R.). Nasal challenge and consecutive measurement by the three methods of rhinomanometry were conducted in a group of 11 volunteers. The three methods gave significantly different histamine concentration thresholds (p = 0.002). Unilateral histamine thresholds as available from A.A.R. and P.A.R. (at a flow of 250 cm3/sec) did not differ significantly (p = 0.299). For A.A.R. and A.P.R., histamine thresholds were assessed at five different pressure values as well as at five different flow values. The thresholds did not appear to be significantly different at any one of those pressure gradients (p = 0.690) or flow values (p = 0.357).