Sarah Chapman takes a look at eczema research priorities identified by the James Lind Alliance Priority Setting Partnership in 2012 and what progress has been made in addressing these.
Next week is National Eczema Week, so this seems a good time to take stock of the questions people want answered about eczema and how far we’ve got with finding evidence to help answer them. I make no apology for shining a light on the work of Cochrane Skin here; their evidence continues to inform much of the work in this area.
Back in 2012, the top priorities for eczema research were identified and published by an NIHR JLA Priority Setting Partnership (PSP). This is one of many PSPs looking at different health conditions, culminating in a list of the Top 10* priorities for future research, agreed by patients, carers and clinicians. These will all be things that are uncertainties, lacking a reliable evidence base. The hope is that new primary research will be commissioned to address these and that these studies will then be incorporated into Cochrane Reviews. I’ve taken a look at the state of the evidence relevant to the eczema Top 10.
Shared priorities (important to both patients and clinicians)
There is evidence available and/or work in progress on three of the four shared priorities.
What is the best and safest way of using topical steroids for eczema: frequency of application, potency, length of time, alternating with other topical treatments, and age limits for treatment?
What is the long term safety of applying steroids to the skin for eczema?
A Cochrane Review on the effectiveness and safety of different ways of using topical steroids for people with eczema got under way recently. There is also a network meta-analysis in progress which aims to assess the effects of different topical treatments for eczema, and to rank them according to their efficacy and safety.
Which emollient is the most effective and safe in treating eczema?
A Cochrane Review on the effects of emollients and moisturisers for eczema draws on 77 studies with 6603 people. The bottom line is that most moisturisers showed some beneficial effects and when combined with active treatments gave better results than the active treatment alone. It could not be established whether one moisturiser is better than another. There is a podcast about the review on emollients and moisturisers.
The NIHR is funding a randomised trial, the Best Emollient for Eczema (BEE) study. Currently in progress, this study compares the acceptability and effectiveness of four emollients commonly used to treat eczema. The study participants are children aged six months to 12 years, with mild, moderate or severe eczema.
Patient and carer priorities in eczema research
There are Cochrane Reviews relating to four of the five patient and carer priorities.
What is the best psychological treatment for itching/scratching in eczema?
This Cochrane Review brings together evidence on psychological and education interventions, used along with conventional topical treatments, for atopic eczema in children. Nine of the ten studies in the review explored educational interventions, most aimed at parents. No clear conclusions could be drawn and the authors highlight what’s needed in future studies. Here’s the podcast about this review.
How much does avoidance of irritants and allergens help people with eczema?
A Cochrane Review on house dust mite reduction and avoidance measures for treating eczema highlighted an evidence gap here, with only very low-certainty evidence available. So, one type of irritant only and no answers.
Another Cochrane Review looked at specific allergen immunotherapy for the treatment of atopic eczema but their findings were generally inconclusive.
There is work under way to investigate whether routine allergy tests could help children with eczema. TEST (Trial of Eczema allergy Screening Tests) is exploring what GPs and parents of children with eczema think about food allergies and routine testing and how a clinical trial of routine allergy testing might work. This work is being funded by the NIHR.
What is the role of diet in treating eczema: exclusion diets and nutritional supplements?
A Cochrane Review on probiotics for children and adults with mild to severe eczema was updated last year, with 27 new studies, bringing the total to 39 studies with 2599 people. The probiotics used were bacteria of the Lactobacillusand Bifidobacteria species, taken alone or with other probiotics, and given with or without prebiotics.
They found that, compared with no probiotic, probiotics probably make little or no difference in eczema symptoms, as rated by the person themselves or a parent of a child with eczema. Also, they may make little or no difference to quality of life in people with eczema. The authors conclude the “use of probiotics for the treatment of eczema is currently not evidence‐based”.
Another Cochrane Review found that “there is no convincing evidence of the benefit of dietary supplements in eczema” and the authors remind us that we should not assume that dietary supplements are safe.
Health professional priorities in eczema research
There is little currently available addressing the top uncertainties for health professionals. However, there are a couple of things to highlight in relation to the question “What is the best and safest way of using drugs that suppress the immune system when treating eczema?”. There is a Cochrane Network Meta-Analysis in progress on systemic treatments for eczema. There is also an NIHR-funded economic evaluation, due to end next month, comparing methotrexate with ciclosporin to treat severe atopic eczema in children.
Another of the health professional priorities was “how effective are interventions to reduce skin infections in the management of eczema?'”. In October 2019, a Cochrane Review was updated that looks at interventions to reduce Staphylococcus aureus in the management of eczema. Disappointingly, the review mostly serves to highlight an evidence gap here. There is low-certainty evidence that topical steroids combined with antibiotics may be associated with small improvements in symptoms compared with topical steroids alone.
Watch this space
So there is much work to be done and it’s good to see some key topics being addressed, and particularly using evolving methods like network meta-analysis. Cochrane Skin did a prioritisation exercise to guide where they focus their work and you can read about that here. There are also opportunities to get involved in the work of Cochrane: this is a good place to find out more.
The top priorities for eczema were identified by people with eczema, parents of children with eczema and clinicians in 2012.
Since then, research has been done to address some of the key questions. For example, reviews have shown that the use of probiotics to treat eczema is not evidence-based and that moisturisers show some beneficial effects.
Many uncertainties remain and there are multiple ongoing studies and reviews hoping to address these.
*The JLA refers to each list as a Top 10 but some, including the Eczema PSP, include more than 10 in their final list. Those ranked lower are also available to future researchers.
Sarah Chapman has nothing to disclose.
Page last updated 05 November 2019