Efficacy of allergen-specific immunotherapy for atopic dermatitis: A systematic review and meta-analysis of randomized controlled trials

Background: Allergen-specific immunotherapy (allergen-SIT) is the only treatment directed at the cause of IgE-mediated allergic diseases. However, there is controversy over the use of SIT for patients with atopic dermatitis. Objective: We performed a systematic review and meta-analysis to assess the efficacy of SIT for patients with atopic dermatitis. Methods: We performed manual searches of reference lists and computerized searches of the MEDLINE, EMBASE, CINAHL, Web of Science, and Cochrane databases (through December 10, 2012) for randomized controlled trials that compared SIT with placebo for patients with atopic dermatitis. The outcome of interest was a dichotomous variable, in terms of treatment success; a meta-analysis was performed by using a random-effects analysis. Subgroup analyses were carried out to evaluate the effects of long-term treatment (more than 1 year), SIT for severe atopic dermatitis, SIT for children, and subcutaneous and sublingual administration of immunotherapy. Results: We analyzed 8 randomized controlled trials that comprised a total of 385 subjects. We found that SIT has a significant positive effect on atopic dermatitis (odds ratio [OR], 5.35; 95% CI, 1.61-17.77; number needed to treat, 3; 95% CI, 2-9). SIT also showed significant efficacy in long-term treatment (OR, 6.42; 95% CI, 1.50-27.52) for patients with severe atopic dermatitis (OR, 3.13; 95% CI, 1.31-7.48), and when administered subcutaneously (OR, 4.27; 95% CI, 1.36-13.39). Conclusions: A meta-analysis provides moderate-level evidence for the efficacy of SIT against atopic dermatitis. However, these findings are based on an analysis of a small number of randomized controlled trials, with considerable heterogeneity among trials.