In past years it has been employed the monoclonal humanized anti-Immunoglobulin IgE (iGE) antibody (Omalizumab) to treat moderate to severe asthma with good results. The rationale for this approach in chronic urticaria is that Omalizumab inhibits the binding of IgE to the high affinity IgE receptor (FceRI) which decreases the FceRI expression on the surface of mast cells and basophils so that immunoglobulin G cross linking of the alpha subunit and basophil degranulation is prevented.The hypothesis the investigators are working on is that monoclonal IgE antibody Omalizumab could be effective in controlling chronic urticaria symptoms in patients non respondent to conventional therapy. The investigators hypothesize that Omalizumab is able to revert the basophil or mast cell activation present in chronic urticaria.