Effectiveness of antibacterial therapeutic clothing vs. nonantibacterial therapeutic clothing in patients with moderate-to-severe atopic dermatitis: a randomized controlled observer-blind pragmatic trial (ABC trial)

Background Increased Staphylococcus aureus (SA) colonization is considered an important factor in the pathogenesis of atopic dermatitis (AD). Antibacterial therapeutic clothing aims to reduce SA colonization and AD inflammation; however, its role in the management of AD remains poorly understood. Objectives To investigate the effectiveness of antibacterial therapeutic clothing+standard topical treatment in patients with moderate-to-severe AD vs. standard therapeutic clothing+standard topical treatment; and, if effectiveness was demonstrated, to demonstrate its cost-effectiveness. Methods A pragmatic double-blinded multicentre randomized controlled trial (NCT04297215) was conducted in patients of all ages with moderate-to-severe AD. Patients were centrally randomized 1:1:1 to receive standard therapeutic clothing or antibacterial clothing based on chitosan or silver. The primary outcome was the between-group difference in Eczema Area and Severity Index (EASI) measured over 52 weeks. Secondary outcomes included patient-reported outcomes (PROs), topical corticosteroid (TCS) use, SA colonization, safety and cost-effectiveness. Outcomes were assessed by means of (generalized) linear mixed-model analyses. Results Between 16 March 2020 and 20 December 2021, 171 patients were enrolled. In total, 159 patients were included (54 in the standard therapeutic clothing group, 50 in the chitosan group and 55 in the silver group). Adherence was high [median 7 nights a week wear (interquartile range 3–7)]. Median EASI scores at baseline and at 4, 12, 26 and 52 weeks were 11.8, 4.3, 4.6, 4.2 and 3.6, respectively, in the standard therapeutic clothing group vs. 11.3, 5.0, 3.0, 3.0 and 4.4, respectively, in the chitosan group, and 11.6, 5.0, 5.4, 4.6 and 5.8, respectively, in the silver group. No differences in EASI over 52 weeks between the standard therapeutic clothing group, the chitosan group [–0.1, 95% confidence interval (CI) –0.3 to 0.2; P=0.53] or the silver group (–0.1, 95% CI –0.3 to 0.2; P=0.58) were found. However, a small significant group×time interaction effect between the standard and silver groups was found (P=0.03), in which the silver group performed worse after 26 weeks. No differences between groups were found in PROs, TCS use, SA skin colonization and healthcare utilization. No severe adverse events or silver absorption were observed. Conclusions The results of this study suggest no additional benefits of antibacterial agents in therapeutic clothing in patients with moderate-to-severe AD.