Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. C URRENT O PINION Omalizumab in chronic urticaria Martin Metz and Marcus Maurer Purpose of review The current EAACI/GA 2 LEN/EDF/WAO treatment guidelines for the management of urticaria recommend omalizumab as fourth-line therapy. Within the last year, many reports of omalizumab treatment in chronic urticaria have been published. Recent findings Two multicenter, randomized, placebo-controlled trials in chronic spontaneous urticaria have shown excellent efficacy of omalizumab. Furthermore, in various case series and case reports, omalizumab has been shown to be effective also in inducible urticarias; however, no randomized placebo-controlled trial has been performed yet to thoroughly investigate the efficacy of omalizumab in inducible urticarias. Summary In this review, all published information on the use of omalizumab in urticaria will be summarized and discussed with special emphasis on reports published within the last year. The available data indicate that omalizumab is an effective and well tolerated drug in antihistamine-resistant chronic urticaria. Keywords anti-immunoglobulin (Ig) E, mast cell, physical urticaria, spontaneous urticaria, Xolair INTRODUCTION Urticaria is a frequent skin condition, which is characterized by transient pruritic wheal and flare type skin reactions and, in some patients, the occur- rence of angioedema. In Europe alone, more than 5 million patients are thought to suffer from persist- ing urticaria symptoms [1 & ], which either occur spontaneously, that is in chronic spontaneous urti- caria, or can be induced, for example as a result of environmental physical stimuli such as pressure, ultraviolet irradiation, heat or cold (physical urtica- ria), or by other means (Fig. 1). Patients with chronic urticaria are often severely impaired in their quality of life [2], with negative effects on sleep, daily activities, school/work life and social interactions. Therefore, the current guidelines of the European Academy of Allergy and Clinical Immunology (EAACI)/Global Allergy and Asthma European Net- work (GA 2 LEN)/European Dermatology Forum (EDF)/World Allergy Organization (WAO) state that the aim of treatment for all types of urticaria is to achieve complete symptom relief [3]. To accomplish complete symptom control, specific underlying causes can be identified and eradicated in some patients with chronic spontaneous urticaria [4]. However, most patients with chronic spontaneous urticaria and all patients with inducible urticaria require symptomatic treatment for effective symp- tom control. The current EAACI/GA 2 LEN/EDF/WAO treat- ment guidelines for the management of urticaria recommend the use of second-generation nonsedat- ing oral H1-antihistamines as first-line therapy. In more than 50% of the patients, symptoms persist with standard dosing of antihistamines [1 & ]. In these patients, it is recommended to increase the dose of the nonsedating H1-antihistamines up to four-fold [3]. Thereafter, among several other third-line and fourth-line options including ciclosporin A, the guidelines suggest the possibility of using omalizu- mab. Omalizumab (Xolair, Novartis, Switzerland and Genentech, USA) is a recombinant humanized monoclonal antibody that binds to immunoglobu- lin (Ig) E. It is specific for circulating free IgE and cannot bind to cell-bound IgE or IgG, as it is engin- eered to bind to the CH 3 domain of the e chain, which is close to the binding site of IgE for FceRI and CD23. Omalizumab has been approved in the Allergie-Centrum-Charite ´, Department of Dermatology and Allergy, Charite ´ – Universita ¨ tsmedizin Berlin, Berlin, Germany Correspondence to Professor Dr med. Marcus Maurer, MD, Department of Dermatology and Allergy, Charite ´ – Universita ¨ tsmedizin Berlin, Charite ´platz 1, D-10117 Berlin, Germany. Tel: +49 30 450 518043; fax: +49 30 450 518972; e-mail: marcus.maurer@charite.de Curr Opin Allergy Clin Immunol 2012, 12:406–411 DOI:10.1097/ACI.0b013e328355365a www.co-allergy.com Volume 12  Number 4  August 2012 REVIEW