Omalizumab : other indications and unanswered questions. 
Omalizumab, a recombinant humanized monoclonal antibody against immunoglobulin (Ig)E, represents a unique therapeutic approach for the treatment of allergic diseases.  This agent acts as a neutralizing antibody by binding IgE at the same site as the high-affinity receptor.  Subsequently, IgE is prevented from sensitizing cells bearing high-affinity receptors.  Inhibition of the biological effects of IgE targets an early phase of the allergic cascade before the generation of allergic symptoms.  Currently, omalizumab has been approved for the treatment of persistent allergic asthma in patients who are poorly controlled with inhaled corticosteroids.  However, other allergic disorders may be amenable to treatment with omalizumab because of its ability to inhibit effector functions of IgE. Studies of omalizumab in the treatment of allergic rhinitis comprise the greater part of the literature pertaining to the use of this agent for clinical indications other than asthma.  This article summarizes clinical trials of omalizumab in allergic rhinitis and examines the evidence regarding the effects of omalizumab on the pathophysiological mechanisms underlying allergic rhinitis.  Additionally, we consider the role of this novel therapeutic agent in combination with specific allergen immunotherapy and discuss other potential indications for omalizumab in IgE-mediated disorders, including food allergy, latex allergy, atopic dermatitis, and chronic urticaria.