H1-antihistamines for chronic spontaneous urticaria: an abridged Cochrane Systematic Review

Background Chronic spontaneous urticaria is characterized by recurrent itchy wheals. First-line management is with H1-antihistamines. Objective We sought to conduct a Cochrane Review of H1-antihistamines in the treatment of chronic spontaneous urticaria. Methods A systematic search of major databases for randomized controlled trials was conducted. Results We included 73 studies with 9759 participants; 34 studies provided outcome data for 23 comparisons. Compared with placebo, cetirizine 10 mg daily in the short and intermediate term (RR 2.72; 95% confidence interval [CI] 1.51-4.91) led to complete suppression of urticaria. Levocetirizine 20 mg daily was effective for short-term use (RR 20.87; 95% CI 1.37-317.60) as was 5 mg for intermediate-term use (RR 52.88; 95% CI 3.31-843.81). Desloratadine 20 mg was effective for the short term (RR 15.97; 95% CI 1.04-245.04) as was 5 mg in the intermediate term (RR 37.00; 95% CI 2.31-593.70). There was no evidence to suggest difference in adverse event rates between treatments. Limitations Some methodological limitations were observed. Few studies for each comparison reported outcome data that could be incorporated in meta-analyses. Conclusions At standard doses, several antihistamines are effective and safe in complete suppression of chronic spontaneous urticaria. Research on long-term treatment using standardized outcome measures and quality of life scores is needed