This is a 24 week double-blind study consisting of up to 11 office visits for people 18 years of age with aspirin exacerbated respiratory disease (AERD). 21 subjects will participate and will be randomized 2:1 to receive Xolair (Omalizumab) or placebo. 14 subjects will receive Xolair and 7 will receive placebo. Xolair is a FDA approved medication for the treatment of moderate to severe allergic asthma. Injections will occur every 2-4 weeks, for 16 weeks. The dosage will be based upon IgE and body weight. Aspirin desensitization will occur 1-3 weeks later. One month after desensitization, the final visit will occur in the GCRC.

Properly selected patients with aspirin exacerbated respiratory disease (AERD) experience benefit in the course of their disease with aspirin desensitization treatment; however, AERD patients are at risk for potentially serious asthmatic reaction when undergoing aspirin desensitization. For this reason, this procedure is currently performed in a monitored setting. We hypothesize that administration of Xolair, a monoclonal anti-IgE antibody, prior to the aspirin desensitization will reduce severity of aspirin-induced respiratory reaction, and that ultimately, use of Xolair will permit this procedure to be performed safely in outpatient settings. This protocol also entails obtaining blood and urine samples to assess the influence of Xolair, compared with placebo. As aspirin induced reaction occurs via heightened release of leukotrienes combined with greater end organ responsiveness to these mediators, we also will be quantifying the impact of prior administration of Xolair, compared with placebo, on the elevation of urinary LTE4 in association with aspirin challenge and with aspirin provoked reaction.