Dietary Elimination for the Treatment of Atopic Dermatitis: A Systematic Review and Meta-Analysis.

BACKGROUND: The influence of diet on atopic dermatitis (AD) is complex, and the use of dietary elimination as a treatment has conflicting views. OBJECTIVE: To systematically review the benefits and harms of dietary elimination for the treatment of AD. METHODS: We searched MEDLINE, Embase, AMED, PsycINFO, and the Cochrane Central Register of Controlled Trials from inception to January 18, 2022, without language restrictions, for randomized controlled trials (RCTs) and observational studies comparing dietary elimination and no dietary elimination for the treatment of AD. We conducted random-effects meta-analyses of eczema outcomes. We used the grading of recommendations, assessment, development, and evaluation approach to assess certainty of evidence (CRD42021237953). RESULTS: Ten RCT (n = 599; baseline median of study mean age, 1.5 years; median of study mean SCOring Atopic Dermatitis index, 20.7, range, 3.5-37.6) were included in the meta-analysis. Compared with no dietary elimination, low-certainty evidence showed that dietary elimination may slightly improve eczema severity (50% with vs 41% without dietary elimination improved the SCOring Atopic Dermatitis index by a minimally important difference of 8.7 points, risk difference of 9% [95% CI, 0-17]), pruritus (daytime itch score [range, 0-3] mean difference, -0.21 [95% CI, -0.57 to 0.15]), and sleeplessness (sleeplessness score [range, 0-3] mean difference, -0.47 [95% CI, -0.80 to -0.13]). There were no credible subgroup differences based on elimination strategy (empiric vs guided by testing) or food-specific sensitization. Insufficient data addressed harms of elimination diets among included RCTs, although indirect evidence suggests that elimination diets may increase the risk for developing IgE-mediated food allergy. CONCLUSIONS: Dietary elimination may lead to a slight, potentially unimportant improvement in eczema severity, pruritus, and sleeplessness in patients with mild to moderate AD. This must be balanced against potential risks for indiscriminate elimination diets including developing IgE-mediated food allergy and withholding more effective treatment options for AD.