Unanswered clinical questions and speculation about the role of anti-immunoglobulin E in atopic and nonatopic disease.

As clinical experience with omalizumab increases, questions arise from clinicians that are not answered in the product insert or clinical reports. How does this drug really work? There surely must be more than the simple reduction of free IgE which, in and of itself, causes no disease. Can omalizumab be used in patients whose IgE level is below 30 or above 700 IU/mL? Can you treat a pregnant asthmatic woman with omalizumab? What are the updated risks for cancer? Is there a risk for omalizumab-treated patients who travel to parasite-endemic areas? What are the implications of skin-prick tests that remain positive after treatment? Does this drug prevent anaphylaxis with enough assurity to use it in conjunction with immunotherapy (IT) or rush IT? Are the complexes formed as a result of therapy problematic, therapeutic, or inconsequential? How long should this drug be used? It is the purpose of this review to examine these clinical issues and present common strategies for approaching each.