Weekly versus daily bathing for people with eczema: results of the Eczema Bathing online randomised controlled trial

Background:

Questions about washing are a high priority for people with eczema (syn. atopic dermatitis, atopic eczema) but are rarely the focus of randomised controlled trials (RCTs).

Objectives:

To assess the impact of weekly bathing compared to daily bathing in people with eczema in the first of a series of eczema citizen science online trials in the United Kingdom.

Methods:

Pragmatic, two-arm, parallel-group superiority RCT. People with self-reported eczema aged ≥1 were eligible, excluding those with very mild eczema (Patient Orientated Eczema Measure (POEM) score ≤ 2). Participants were allocated (1:1) using minimisation, balancing on eczema severity (POEM), age and usual method of bathing, to either the weekly bathing group (bath or shower once or twice a week) or the daily bathing group (≥6 times a week) for 4 weeks. Participants were not blinded to their allocation. Primary outcome was participant reported eczema symptoms collected weekly over four weeks using POEM (range 0 to 28, higher scores more severe).

Results:

438 people with eczema (108 aged <16 years) were randomised between 29th January and 8th July 2024: 218 to daily bathing and 220 to weekly bathing. The primary analysis included 195 participants (89%) allocated to daily bathing and 193 (88%) to weekly bathing who completed at least one follow-up questionnaire. Mean POEM scores at baseline, 1, 2, 3 and 4 weeks, were 14.5 [standard deviation 5.7], 11.7 [5.9], 12.2 [5.9], 11.7 [6.7] and 11.6 [6.5], respectively, in the daily bathing group, and 14.9 [6.3], 12.1 [6.8], 11.3 [6.7], 10.5 [7.0] and 10.6 [7.2] in the weekly bathing group. The adjusted difference in mean POEM score over 4 weeks for weekly versus daily bathing was -0.4 (95% confidence interval -1.3 to 0.4, p = 0.30). Process evaluation data highlighted participants’ experiences of making changes to bathing routines, including barriers to following the allocated routine. No serious unintended effects or harms were reported.

Conclusions:

The trial found no evidence of a difference in eczema symptoms between bathing or showering weekly compared to daily. These results are helpful for people with eczema, giving them the freedom to choose what suits them best.