Specific allergen immunotherapy (SIT) is an effective allergy treatment, but it is unclear whether SIT is effective for atopic eczema (AE). We undertook a systematic review to assess SIT efficacy and safety for treating AE.Methods:
We searched databases, ongoing clinical trials registers, and conference proceedings up to July 2015. Randomized controlled trials (RCTs) of SIT using standardized allergen extracts, compared with placebo/control, for treating AE in patients with allergic sensitization were eligible.Results:
We identified 12 eligible trials with 733 participants. Interventions included subcutaneous (six trials), sublingual (four trials), oral or intradermal SIT in children/adults allergic to house dust mite (10 trials), grass pollen or other inhalants. Risk of bias was moderate, with high loss to follow-up and nonblinding as the main concerns. For our primary outcomes, three studies (208 participants) reported no significant difference – patient-reported global disease severity improvement RR 0.75 (95% CI 0.45, 1.26); and eczema symptoms mean difference −0.74 on a 20-point scale (95% CI −1.98, 0.50). Two studies (85 participants) reported a significant difference – SIT improved global disease severity RR 2.85 (95% CI 1.02, 7.96); and itch mean difference −4.20 on a 10-point scale (95% CI −3.69, −4.71). Meta-analysis was limited due to extreme statistical heterogeneity. For some secondary outcomes, meta-analyses showed benefits for SIT, for example investigator-rated improvement in eczema severity RR 1.48 (95% CI 1.16, 1.88; six trials, 262 participants). We found no evidence of adverse effects. The overall quality of evidence was low.Conclusion:
We found no consistent evidence that SIT is effective for treating AE, but due to the low quality of evidence further research is needed to establish whether SIT has a role in AE treatment.