A randomized placebo-controlled double-blind pilot study of methotrexate in the treatment of H1 antihistamine-resistant chronic spontaneous urticaria.

Background: Chronic urticaria not responsive to antihistamines is a difficult disease to manage. Methotrexate has been used in difficult chronic urticarias with some benefit.

Objective: To evaluate the efficacy of methotrexate in the treatment of chronic spontaneous urticaria poorly responsive to H1 antihistaminics.

Methods: In a randomized double-blind trial at the Department of Dermatology and Venereology of a tertiary care centre, 29 patients with chronic spontaneous urticaria not responding well to H1 antihistaminics were recruited. Patients were randomly allocated to receive either a weekly dose of oral methotrexate 15 mg or placebo (calcium carbonate) for a total duration of 12 weeks, after which treatment was stopped and patients were followed up for relapse of urticaria. Each group also received levocetrizine 5 mg once daily for symptom control. Primary outcome measured was a reduction by >2/3 rd of baseline urticaria scores after 12 week therapy. Secondary outcome was a reduction in antihistamine requirement after stopping therapy.

Results: Fourteen patients were randomized to the methotrexate group and fifteen patients to the placebo group. Out of 17 patients who completed therapy, the primary outcome was achieved by 3.5 ± 1.9 (out of 10) patients in the methotrexate group and by 3.67 ± 1.03 (out of 7) patients in the placebo group (P > 0.05). Ten patients followed up, after stopping therapy, for a mean period of 3.5 ± 2.4 months; 3 remained in remission and 7 had relapsed. One patient had uncontrollable nausea and vomiting after taking methotrexate and was withdrawn from the study. The placebo group did not experience any side effects.

Conclusions: Methotrexate 15 mg weekly for 3 months did not provide any additional benefit over H1 antihistamines in this study but an adequately powered study with longer follow up is required to assess its utility.