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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
Adding emollients to children’s bath water does not significantly improve their eczema. Prescriptions should focus on emollients applied directly to the skin or used as a soap substitute.
Using emollients to lock in moisture is the standard treatment for childhood eczema. These can be applied in a number of ways, but there is uncertainty surrounding their use as a bath additive.
This NIHR-funded year-long trial included 482 children, mostly with mild eczema. It found there was little change in skin-related outcomes or quality of life between those that did or did not have emollients poured into their bath.
Why was this study needed?
Eczema often starts in childhood, affecting between 10 to 30% of children. It causes skin inflammation and itching which can significantly impact quality of life.
The condition varies in severity, and periods of worsening symptoms are common. These flare-ups make skin vulnerable to cracks, bleeding and infection.
There is no cure for eczema. It is primarily managed by emollients, a general term for creams, ointments, lotions, oils and gels which keep the skin soft. These create a barrier to lock in moisture. They can be applied directly to the skin, as a soap substitute or as a bath additive. Emollient bath additives are commonly prescribed, costing the English NHS more than £17m a year in primary care alone.
There is uncertainty as to whether bath emollients are effective and if so for which severity or types of eczema.
What did this study do?
The BATHE randomised controlled trial compared bath emollients in addition to usual care with usual care alone.
The study involved 96 general practices across England and Wales. It took place over a 12-month period with 482 children aged 1 to 11 years. Most children had mild or moderate eczema, 62 had severe eczema, and half were using corticosteroid cream. The patient-oriented eczema measure (POEM) questionnaire was filled out weekly by parents or carers during the study.
Only 74% of the intervention group used bath additives at every bath, raising questions around adherence to treatment, both within and outside of the trial environment. The control group were asked not to use bath emollients, though 7% did. Other limitations include missing outcome data for 12% of the children.
What did it find?
- Little difference was observed between the two groups. The baseline POEM score (0-7 mild, 8-16 moderate, 17-28 severe) was 9.5 (SD 5.7) in the intervention group and 10.1 (SD 5.8) in the control group. The mean POEM score over the first 16-week period was 7.5 (SD 6.0) in the intervention group and 8.4 (SD 6.0) in the control group.
- After controlling for baseline severity and confounders, as well as clustering of patients within centres and responses within patients over time, the POEM score in the control group was 0.41 points higher (95% confidence interval [CI] -0.27 to 1.10). This is much lower than the minimal clinically important difference of 3 points.
- There was no difference between groups in quality of life at 52 weeks.
- Mean annual costs to the NHS were estimated at £180.50 per patient for the bath additives group and £166.12 per patient for the control group.
- Subgroup analysis revealed no difference for children with moderate or severe eczema, though there were few cases of severe eczema in this trial. There was an improvement in children less than 5 years old using bath emollients, as the adjusted mean POEM score in the control group was 1.29 points higher (95% CI 0.33 to 2.25). Although not clinically important according to POEM scoring, it may warrant further investigation. Similarly, those that bathed 5 or more times a week also seemed to benefit from the use of bath emollients, as the control group POEM score was 2.27 points higher (95% CI 0.63to 3.91).
What does current guidance say on this issue?
NICE 2007 guidance states that eczema should be managed according to the severity of the condition. This stepped approach allows treatment to be tailored to the individual, taking into account likely flare-ups.
Application of emollients should be the mainstay of treatment for the condition and need to be used even when the skin is clear. A choice of unperfumed emollients should be offered, and a combination may be used every day to moisturise, wash and at bath-time. Corticosteroid creams are used of varying strengths depending on the severity of flare-ups. In severe eczema, other systemic treatments are used including phototherapy.
What are the implications?
For the majority of children, there appears to be little benefit adding the emollients used in this trial (Oilatum™, Balneum™ and Aveeno™) to the bath in addition to creams or emollients for direct application.
The difficulties in using emollient bath additives, even in the intervention group, are also worth noting. It confirms previous research showing that eczema treatments may be seen as messy and this could lead to under-use.
It is important that children's caregivers are aware of the need for regular application, regardless of the type of emollient used, but that adding these products to the bath is in most cases unnecessary and adds costs for the NHS.
Citation and Funding
Santer M, Ridd MJ, Francis NA, et al. Emollient bath additives for the treatment of childhood eczema (BATHE): multicentre pragmatic parallel group randomised controlled trial of clinical and cost effectiveness. BMJ. 2018;361:k1332
This project was funded by the National Institute for Health Research Health Technology Assessment Programme (project number 11/153/01).
Bibliography
NHS website. Atopic eczema. London: Department of Health and Social Care; updated 2016.
NICE. Atopic eczema in under 12s: diagnosis and management. CG57. London: National Institute for Health and Care Excellence; 2007.
NICE. Eczema- atopic. Clinical Knowledge Summary. London: National Institute for Health and Care Excellence; 2007.
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