We performed a Cochrane systematic review and meta-analysis to assess the efficacy of specific allergen immunotherapy (SIT) for the treatment of atopic eczema (AE).
We searched electronic databases, trial databases, and abstracts from recent allergy meetings up to July 2015. There were no language or publication status restrictions. We included randomized controlled trials (RCTs) of SIT using standardized allergen extracts compared to placebo or standard treatment in children and adults with proven allergic sensitization, administered via any route.
We identified 12 RCTs with 733 participants. Study quality was mixed, with high loss-to-follow-up in eight trials and non-blinded outcome assessment in two trials. Ratio of participant/parent-assessed global disease improvement was significantly higher with SIT in one trial RR2.85 (95%CI 1.02, 7.96) but not in another RR0.75 (95%CI 0.45, 1.26). Data were not pooled due to high heterogeneity. Participant/parent-assessed eczema symptoms did not differ significantly between treatment groups in two trials: SCORAD C in favour of SIT MD0.71 (95%CI -0.50, 1.98); sleep disturbance MD0.49 (95%CI -0.06, 1.03). Data for severity of itch were not pooled due to extreme heterogeneity, with one open-label trial reporting a significant difference in favour of SIT, and two other trials reporting no significant difference. SIT was not associated with increased adverse reactions.
We found a lack of high quality evidence that SIT is an effective treatment for AE. There is a need for methodologically rigorous RCTs using high-quality allergen formulations with a proven track record in other allergic conditions, and reporting patient-centered outcome measures.