IGHE and perennial allergic rhinitis: The specific aims were to: (1) determine if the efficacy of omalizumab differs between patients with different levels of pre-treatment serum eosinophil as well as total and free IgE, asthma severity, allergen profile, and history of perennial allergic rhinitis (PAR); (2) examine changes in levels of circulating total and free IgE during omalizumab treatment.