It has previously been shown that in patients with unified allergic airway disease, using inhaled fluticasone alone (100 micrograms per day) produced a 1.2 doubling dilution (dd) shift in the provocative concentration of methacholine required to reduce forced expiratory volume (FEV1) by 20% (PC20). However when adding nasal fluticasone to the inhaled steroid, there was a 1.79 dd shift. This difference (0.58 dd, 95% CI 0.78, 1.95) was not statistically significant. However the combined treatment did result in significant improvement in rhinitis quality of life, nasal inflammation and inspiratory flow.