Pruritus (itch) is a cardinal symptom in atopic dermatitis (AD). To evaluate the timing and effect of dupilumab on itch. Analysis of data from 1505 patients with moderate to severe AD included in 4 randomized controlled studies, treated for up to 52weeks. Adults received dupilumab 300mg every 2weeks or placebo monotherapy (SOLO 1: NCT02277743; SOLO 2: NCT02277769), with concomitant topical corticosteroids (CHRONOS: NCT02260986); adolescents (≥12 to <18y) were treated with dupilumab monotherapy every 2weeks (200mg for baseline weight of <60kg; 300mg for baseline weight of ≥60kg) or placebo (AD ADOL: NCT03054428). Dupilumab showed significant rapid improvements from baseline in daily Peak Pruritus Numerical Rating Scale scores versus placebo, by day 2 in adults and day 5 in adolescents. At treatment end, dupilumab vs placebo/control had greater least-squares mean percent change from baseline in the weekly average of Peak Pruritus Numerical Rating Scale scores: SOLO -47.5% vs -20.5%; AD-ADOL -47.9% vs -19.0%; CHRONOS -57.3% vs -30.9% (P<.0001 for all). Short duration of monotherapy trials (16weeks). Across 4 randomized trials, dupilumab treatment showed rapid and sustained improvements in the magnitude of itch, starting with first dose; responses progressively increased and were sustained through to the end of treatment, up to 1year.