What is the clinical effectiveness of including emollient bath additives in the treatment of childhood eczema? Findings from BATHE multi-centre randomised controlled trial
Problem
Childhood eczema is common and usually managed in primary care. Emollient bath additives are widely prescribed for childhood eczema yet evidence for their benefit is lacking. We aimed to determine the clinical and cost-effectiveness of including bath additives in the standard management of childhood eczema.
Approach
BATHE was a pragmatic randomised, open-label, multi-centre superiority trial with two parallel groups.Participants were recruited through mail-out and opportunistic recruitment from 96 practices in Wales, West of England and Southern England.Children were eligible if aged over 12 months and less than 12 years, fulfilling UK Diagnostic Criteria for Atopic Dermatitis. Children with inactive or very mild eczema (Nottingham Eczema Severity Scale 5 or less) were excluded, as were children who bathed less than once a week, or whose carers were not willing to accept randomisation. 483 were randomised and one withdrew, leaving 482 children in the trial, mean age 5 years.The intervention group were prescribed emollient bath additives by their usual clinical team and were asked to use them regularly for 12 months. The control group were asked to use no bath additives for 12 months. Both groups were advised to continue with standard eczema management, including regular leave-on emollients and topical corticosteroids when required.
Findings
The primary outcome measure was eczema control assessed by Patient Oriented Eczema Measure (POEM, range 0 (clear) to 28 (most severe)) weekly for 16 weeks. Secondary outcomes included eczema severity over 1 year (4-weekly POEM); number of consultations for eczema exacerbations; Dermatitis Family Impact questionnaire; generic QoL (Child Health Utility-9D); and resource utilisation.At least one post-baseline POEM was completed by 96.5% (465/482) of participants. Mean baseline POEM was 9.5 (s.d. 5.7) in the bath additives group and 10.1 (s.d. 5.8) in the no bath additives group. Mean POEM over the 16-week period was 7.5 (s.d. 6.0) in the bath additives group and 8.4 (6.0) in the no bath additives group. There was no statistically significant difference in weekly POEM scores between groups over 16 weeks. After controlling for baseline severity and confounders (ethnicity, topical corticosteroid use, soap substitute use) and allowing for clustering of participants within centres and responses within participants over time, POEM scores in the no bath additives group were 0.41 points higher than in the bath additives group (95% CI -0.27 to 1.10), below the minimal clinically important difference of 3 points. There was no difference between groups in secondary outcomes or adverse effects.
Consequences
We found no evidence of clinical benefit from including emollient bath additives in the management of childhood eczema. Further research is needed into optimal regimens for leave-on emollient and soap substitutes for eczema.