Safety of Methotrexate in Chronic Urticaria Unresponsive to Omalizumab

Omalizumab (humanized anti-immunoglobulin IgE) is currently the first choice of treatment for chronic urticaria refractory to high-dose second-generation antihistamines (sgAH). Despite its high safety profile, response to omalizumab is insufficient in one-third of patients. Some studies have suggested that methotrexate is effective in antihistamine-refractory chronic urticaria, but there are no studies on its efficacy and safety in patients unresponsive to omalizumab. This retrospective study aimed to investigate the clinical effectiveness and adverse effects of methotrexate in patients with chronic urticaria unresponsive to omalizumab + high-dose sgAH. The patients were evaluated in terms of age at disease onset, duration of the urticaria episode before methotrexate therapy, treatment before methotrexate therapy, final treatment, treatment responses, 7-day urticaria activity score (UAS7) before and after treatment, and total IgE levels. Methotrexate was administered subcutaneously at a dose of 15 mg once weekly as monotherapy or in combination with other drugs to 10 chronic urticaria patients with a history of nonresponse to omalizumab + high-dose sgAH. The mean age of the patients was 44.6±11.5 (31-65) years, and 9 (90%) of the patients were female. The mean duration of methotrexate therapy was 5.1±2.4 months (1.5-9 months). Complete response or well-controlled response was observed in 70% of the patients and partial response was observed in 1 patient (10%). Methotrexate was well tolerated by 80% of the patients. Methotrexate seems to be a useful treatment option both as monotherapy or combined therapy in patients resistant to omalizumab + sgAH.