Scoping systematic review of treatments for eczema

Abstract

BackgroundEczema is a very common chronic inflammatory skin condition.ObjectivesTo update the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) systematic review of treatments for atopic eczema, published in 2000, and to inform health-care professionals, commissioners and patients about key treatment developments and research gaps.Data sourcesElectronic databases including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Skin Group Specialised Register, Latin American and Caribbean Health Sciences Literature (LILACS), Allied and Complementary Medicine Database (AMED) and Cumulative Index to Nursing and Allied Health Literature (CINAHL) were searched from the end of 2000 to 31 August 2013. Retrieved articles were used to identify further randomised controlled trials (RCTs).Review methodsStudies were filtered according to inclusion criteria and agreed by consensus in cases of uncertainty. Abstracts were excluded and non-English-language papers were screened by international colleagues and data were extracted. Only RCTs of treatments for eczema were included, as other forms of evidence are associated with higher risks of bias. Inclusion criteria for studies included availability of data relevant to the therapeutic management of eczema; mention of randomisation; comparison of two or more treatments; and prospective data collection. Participants of all ages were included. Eczema diagnosis was determined by a clinician or according to published diagnostic criteria. The risk of bias was assessed using the Cochrane Collaboration risk-of-bias tool. We used a standardised approach to summarising the data and the assessment of risk of bias and we made a clear distinction between what the studies found and our own interpretation of study findings.ResultsOf 7198 references screened, 287 new trials were identified spanning 92 treatments. Trial reporting was generally poor (randomisation method: 2% high, 36% low, 62% unclear risk of bias; allocation concealment: 3% high, 15% low, 82% unclear risk of bias; blinding of the intervention: 15% high, 28% low, 57% unclear risk of bias). Only 22 (8%) trials were considered to be at low risk of bias for all three criteria. There was reasonable evidence of benefit for the topical medications tacrolimus, pimecrolimus and various corticosteroids (with tacrolimus superior to pimecrolimus and corticosteroids) for both treatment and flare prevention; oral ciclosporin; oral azathioprine; narrow band ultraviolet B (UVB) light; Atopiclair™ and education. There was reasonable evidence to suggest no clinically useful benefit for twice-daily compared with once-daily topical corticosteroids; corticosteroids containing antibiotics for non-infected eczema; probiotics; evening primrose and borage oil; ion-exchange water softeners; protease inhibitor SRD441 (Serentis Ltd); furfuryl palmitate in emollient; cipamfylline cream; andMycobacterium vaccaevaccine. Additional research evidence is needed for emollients, bath additives, antibacterials, specialist clothing and complementary and alternative therapies. There was no RCT evidence for topical corticosteroid dilution, impregnated bandages, soap avoidance, bathing frequency or allergy testing.LimitationsThe large scope of the review coupled with the heterogeneity of outcomes precluded formal meta-analyses. Our conclusions are still limited by a profusion of small, poorly reported studies.ConclusionsAlthough the evidence base of RCTs has increased considerably since the last NIHR HTA systematic review, the field is still severely hampered by poor design and reporting problems including failure to register trials and declare primary outcomes, small sample size, short follow-up duration and poor reporting of risk of bias. Key areas for further research identified by the review include the optimum use of emollients, bathing frequency, wash products, allergy testing and antiseptic treatments. Perhaps the greatest benefit identified is the use of twice weekly anti-inflammatory treatment to maintain disease remission. More studies need to be conducted in a primary care setting where most people with eczema are seen in the UK. Future studies need to use the same core set of outcomes that capture patient symptoms, clinical signs, quality of life and the chronic nature of the disease.FundingThe National Institute for Health Research Programme Grants for Applied Research programme.

A programme of research to set priorities and reduce uncertainties for the prevention and treatment of skin disease

“…l systematically reviewing all possible treatments of eczema in an overarching review 223 l developing a database of all eczema RCTs l developing core outcome sets for eczema trials l prioritising future research in partnership with patients l submitting an application for a new clinical trial.…”

“…223 The yield of 287 new RCTs covering 92 different treatments provides a much firmer evidence base for supporting or refuting currently used eczema treatments and for guiding commissioners, health-care providers, HCPs and patients with regard to those that are currently not used on the NHS. We have found sufficient evidence to support the use of topical corticosteroids and calcineurin inhibitors for treating eczema flares reactively, and for the prevention of flares by using them proactively for two consecutive days each week.…”

“…The review was conducted as part of this NIHR Programme Grants for Applied Research award (RP-PG-0407-10177) and is published in full as a separate report. 223 ECZEMA TREATMENT WORK PROGRAMME NIHR Journals Library www.journalslibrary.nihr.ac.uk…”

“…223 Overviews of existing systematic reviews are also needed, as is the application of mixed treatment comparisons for understanding more about the relative value of treatments that have not yet been compared in head-to-head trials.…”

“…The full report is published as a separate report 223 The Global Resource of EczemA Trials database Describes the development of an online, searchable database that includes all RCTs and systematic reviews of eczema treatments. This resource is intended to reduce duplication of effort in searching for research evidence and should be particularly helpful for systematic reviewers and guideline writers …”