Recent advances in the treatment of refractory chronic spontaneous urticaria

Chronic spontaneous urticaria (CSU) is a common disorder that has a prevalence of 0.5% - 1% in the general population. Although H1 antihistamine in effective mainstay of CSU, one out of 5 is resistant to conventional antihistamine monotherapy. The major therapeutic advance in recent years has been in third-line treatment with omalizumab, a IgG humanized monoclonal anti-immunoglobulin E (anti-IgE) antibody that prevents binding of IgE to the high-affinity IgE receptor (FceR1). Several multicenter randomized controlled trials have shown safety and efficacy of omalizumab in intractable CSU. In well-controlled clinical trials in patients with refractory CSU, add-on therapy with subcutaneous omalizumab 300 mg every 4 weeks for 12 or 24 weeks significantly reduced the severity of itching, and the number and size of hives, and increased patients` health-related quality of life compared with placebo. Rates of complete response were significantly higher in the omalizumab group (relative risk, 4.55; P<.00001). The introduction of omalizumab as an add-on therapy to H1 antihistamines as a management option has markedly improved the therapeutic possibilities and quality of life in CSU patients. Nevertheless, there are still many patients who do not tolerate or benefit from existing therapies including omalizumab. There are ongoing studies investigating treatment potential of novel therapeutic targets in CSU.