Multi Immunotherapy to Test Tolerance and Xolair

The investigators will enroll multi food allergic subjects (4-55 years of age) with proven multi food allergies. The investigators anticipate enrolling 70 subjects with multi food allergies at more than one site. Subjects must have food specific Immunoglobulin E \>4 kilo Units/Liter for each allergen or a skin test reactivity to each food allergen greater than or equal to 6mm wheal diameter. In addition, subjects must have a total Immunoglobulin E \<2,000 kilo Units/Liter, a clinical reaction during a double blind placebo controlled food challenge (DBPCFC) with food protein/powder to establish sensitivity to given food protein/powder (pecan, milk, egg, peanut, almond, wheat, cashew, sesame seed, soy, walnut, hazelnut, shrimp, cod, salmon) and no clinical reaction during placebo (oat) as per Chemistry Manufacturing and Control section of Investigational New Drug. Each subject is planned to be enrolled in the active phase of the study for 36 weeks. Food protein and powder will be obtained and prepared as per Investigational New Drug 14831 and will be in compliance with all applicable regulations. Omalizumab is approved by the European Medicines Agency (European FDA) for patients with severe asthma \>6 years of age, and by the US FDA for patients \>12 years of age. Omalizumab will be dosed according to Genentech Dosing Omalizumab will be provided by the site.