Abstract
Objective To systematically synthesise the benefits and harms of add-on oral antihistamines for managing atopic dermatitis (eczema).
Design Systematic review and network meta-analysis of randomised trials.
Data sources Medline, Embase, CENTRAL, the United States Food and Drug Administration, and the European Medicines Agency databases from database inception to 5 May 2025.
Study selection Randomised trials assessing add-on oral H1 antihistamines, H2 blockers, mast cell stabilisers (nedocromil sodium and sodium cromoglycate), or their combinations. Paired reviewers independently screened records, extracted data, and assessed risk of bias using a modified Cochrane Risk of Bias tool version 2.
Methods Random effects bayesian meta-analyses synthesised atopic dermatitis severity (oSCORAD—objective scoring atopic dermatitis, 0-83; minimal important difference 8.2; lower better), itch severity (numerical rating scale, 0-10; minimal important difference 3; lower better), sleep disturbance, atopic dermatitis related quality of life, and harms. The network meta-analysis GRADE (Grading of Recommendations Assessment, Development and Evaluation) and Core GRADE approaches informed certainty of evidence ratings.
Results 47 trials enrolled 6230 children and adults with primarily moderate to severe atopic dermatitis. With moderate certainty, compared with placebo, adding a first generation or second generation H1 antihistamine likely resulted in a small reduction in atopic dermatitis severity (mean difference -1.87, 95% credible interval -3.47 to -0.27) and itch severity (-0.89, -1.41 to -0.37). Although statistically detectable, these effects are well below established minimal important differences (smallest change in an outcome that a patient would identify as important).








