Anti-IgE medications are used to treat asthma, chronic spontaneous urticaria (hives), and nasal polyps. They also have other uses, such as managing allergic reactions. These medications work by blocking immunoglobulin E (IgE), a substance in your body that triggers symptoms of allergic reactions related to foods. By preventing IgE from attaching to cells, these medications help reduce symptoms like wheezing, itching, and nasal congestion. Anti-IgE medications are typically available as injections. Examples include Xolair (omalizumab).