Effect of omalizumab on patients with chronic urticaria.

BACKGROUND: Chronic urticaria (CU) is often difficult to treat. Approximately 40% to 50% of patients with no apparent cause are believed to have an associated autoimmune profile that may play a pathogenetic role. OBJECTIVES: To describe 3 patients with CU refractory to conventional treatment who responded to omalizumab therapy. METHODS: Treatment was maximized with antihistamines, antileukotrienes, and histamine2 blockers with no improvement. Systemic steroids provided only temporary relief. Laboratory workup revealed 1 patient with a low IgE level and elevated anti-IgE receptor antibody level, 1 patient with an elevated IgE level but a normal anti-IgE receptor antibody level, and 1 patient with a very elevated IgE level and an elevated anti-IgE receptor antibody level. All 3 patients were prescribed omalizumab therapy every 2 weeks. RESULTS: Two patients had total clearing of urticaria within 1 week and 1 patient within 6 weeks of starting omalizumab therapy. The patient with the elevated anti-IgE receptor antibody level had normalization of the level after starting treatment. CONCLUSIONS: Omalizumab may have a beneficial effect in the treatment of CU. Further studies are needed to confirm this effect and better elucidate the mechanism for the observed improvement.