IgE (immunogloblin E) IgE is one of the main players in type I hypersensitivity responses and reducing its circulating levels using omalizumab can be an effective treatment in a number of allergic disorders including allergic asthma, hay-fever and food allergies. Using omalizumab to treat patients with severe asthma can have many benefits. For example, many people are able to move off high-dose glucocorticoid therapy and thus avoid the Cushingoid side-effects associated with it.