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.