Peak inspiratory flow rate is more sensitive than acoustic rhinometry or rhinomanometry in detecting corticosteroid response with nasal histamine challenge

Nasal histamine challenge testing is a standard method of assessing upper airway hyperreactivity although there is still debate as to the best measure of response. The aim of the study was to evaluate peak nasal inspiratory flow rate (PIFR) as an endpoint during histamine challenge and compare this with rhinomanometry (Rhino) and acoustic rhinometry (AR). Twenty two patients with perennial allergic rhinitis (PAR) were enrolled into a 2-way randomised crossover study comparing placebo with intra-nasal mometasone furoate (MF) 200 mg once daily, with laboratory measurements of PIFR, AR and Rhino being made during histamine nasal challenge after each 10-14 day treatment period. Patients also recorded their domiciliary nasal symptoms and PIFR on a daily basis. With nasal challenge testing using PIFR PC30 there was a significant (p < 0.05) difference between MF and placebo but not with PC30 AR or PC175 Rhino. There was also significant (p < 0.05) improvement in terms of domiciliary total nasal symptom scores but not domiciliary PIFR. In conclusion PIFR after nasal challenge with histamine is a sensitive test of response to treatment with intra-nasal corticosteroids in PAR.