Background: Chronic spontaneous urticaria (CSU) is treated in adults with 2nd-generation antihistamines, up-dosed to 4-times normal, if necessary. If symptoms are not relieved, treatment with omalizumab (a monoclonal antibody to IgE) is recommended. A similar protocol is used in the pediatric population, yet little is known of its efficacy in children.
Objectives: To summarize our two-center experience in treating children with recalcitrant CSU with omalizumab.
Methods: A retrospective study conducted in 2 tertiary-care centers. Children < 18 years old suffering from CSU treated with omalizumab as third-line add-on therapy were included. Patients were followed-up throughout omalizumab therapy or until their condition resolved.
Results: Thirteen patients (8 females; 5 male) diagnosed with CSU presented between ages 6- 16.9 years, of whom 4 (31%) had accompanying angioedema, 7 (54%) had positive autoimmune antibodies.
Eight patients (61%) responded effectively to omalizumab, as opposed to 80% commonly reported in adults. In the 5 (31%) non-responders, up-dosing omalizumab (>300 mg/ 4 weeks) was ineffective; other lines of therapy (e.g. cyclosporine A, corticosteroids) provided symptom relief. This suggests that the pathophysiology of their CSU was not mediated solely by IgE, but rather by another autoimmune mechanism, supported by the relatively high rate of autoimmune antibodies (54%) and autoimmune diseases (23%) seen in our pediatric patients. Yet, no direct correlation between the presence of autoimmune antibodies and response rate to omalizumab was evident.
Conclusion: Children with recalcitrant CSU respond well to omalizumab, yet at poorer rates than adults.
