The link between allergic inflammation of the upper and lower airways is well established with up to 40% of asthmatics considered to have concomitant allergic rhinitis. In addition to cysteinyl leukotrienes and histamine, immunoglobulin E (IgE) is implicated in allergic inflammation which suggests that modalities directed against such molecules could play an important role towards treatment of the unified airway.

Vignola et al investigated moderate to severe asthmatics with concomitant persistent allergic rhinitis (n = 405) in a multicentre, randomised, double blind, placebo controlled, parallel group study. They evaluated the effects of anti-IgE therapy with omalizumab (in addition to inhaled or nasal corticosteroids) in terms of primary end points of exacerbations of asthma and changes in disease related quality of life. Inclusion criteria included an IgE level of 30–1300 IU/ml plus at least one positive skin prick test to indoor allergens. Fewer patients experienced an asthma exacerbation with omalizumab than with placebo (21% v 30%, p = 0.02), and a greater proportion of patients on omalizumab than on placebo showed improvement in both asthma and rhinitis quality of life questionnaires (58% v 41%, p<0.001). There was no difference in serious adverse effects.

Despite a marked placebo effect, the authors conclude that omalizumab, when used in combination with standard treatment, is effective in reducing exacerbations of asthma and confers clinically relevant improvements in quality of life. The effectiveness and “real life” acceptability of omalizumab injections remain to be established. Moreover, how omalizumab compares with pharmacotherapy attenuating the effects of cysteinyl leukotrienes and histamine in allergic airways disease requires evaluation.