Efficacy of methotrexate as add on therapy to H1 antihistamine in difficult to treat chronic urticaria: A systematic review and meta-analysis of randomized clinical trials.

A systematic review and meta-analysis of randomized clinical trials (RCTs) to evaluate efficacy of add on methotrexate in chronic urticaria. "PubMed" and "Google Scholar" were systematically searched to identify randomized clinical trials with methotrexate in patients with chronic urticaria not responding to second generation antihistamines. Odds ratios and 95% confidence interval were calculated for estimation of efficacy.