Omalizumab is a safe and effective treatment for antihistamine-refractory chronic spontaneous urticaria (CSU) but is insufficient in one-third of patients. For serious cases in which omalizumab is ineffective, cyclosporine or methotrexate may be preferred. Most drug trials in CSU have focused on omalizumab or cyclosporine monotherapy.
A standard dose of second-generation H1 -antihistamines is recommended as the first-line treatment of chronic spontaneous urticaria (CSU), previous studies have found that approximately 20-50% of CSU children fail to control their symptoms and required step-up treatments.