How effective and cost-effective is silk therapeutic clothing for the management of eczema in children (results of the CLOTHES randomised controlled trial)
The role of specialised clothing in the management of eczema is poorly understood. Silk clothing is currently available on prescription in the UK, but the evidence-base supporting its use is limited. This study evaluated the effectiveness of silk clothing when used in addition to usual eczema care over a period of six-months.
Parallel group randomised controlled trial of children (1 to 15 years) with moderate to severe eczema recruited from secondary and primary care in five UK centres (Nov 2013 to May 2015). Randomisation (1:1) to usual care, or usual care plus 100% sericin-free, knitted silk garments (DermaSilkTM or DreamskinTM) was stratified by age and recruiting centre and used a secure web based system. Three sets of garments were supplied per participant, to be worn day and night for up to 6-months. Primary outcome of eczema severity was assessed at baseline, 2, 4 and 6 months, by nurses blinded to treatment allocation using the Eczema Area Severity Index (EASI), which was log-transformed for analysis. Secondary outcomes: patient-reported eczema severity (Patient-Oriented Eczema Measure (POEM) and patient global assessment (PGA)), nurse-assessed eczema severity (Three Item Scale (TIS) and investigator global assessment (IGA)), use of eczema medications, quality of life, number of skin infections and cost-effectiveness.
Three hundred children were randomised (42% female, mean age 5 years). EASI was assessed at least once at follow up for 282/300 (94%) children (n = 141 in each group). The garments were worn for at least 50% of the time by 82% in the silk clothing group. Geometric mean EASI scores at baseline, 2, 4 and 6 months were 8.4, 6.6, 6.0, 5.4 for usual care and 9.2, 6.4, 5.8, 5.4 for silk clothing. There was no evidence of any difference between the groups in EASI score averaged over all follow up visits (ratio of geometric means = 0.95, 95% CI 0.85 to 1.07; p=0.43). This confidence interval is approximately equivalent to a difference of -1.5 to 0.5 in the original EASI scale units, which is not clinically meaningful. All secondary analyses were supportive of the primary outcome with the exception of participant-reported POEM and PGA, which showed a small difference favouring silk clothing, but were likely to be susceptible to detection bias due to lack of blinding. The number of participants reporting at least one skin infection that required antibiotic/antiviral treatment was 39/141 (28%) and 36/142 (25%) for usual care and silk clothing respectively. The incremental cost per QALY was £56,881 from an NHS perspective, suggesting that silk garments are unlikely to be cost-effective within currently accepted thresholds.
Specialist silk clothing is unlikely to provide additional benefit to usual care for children with a history of moderate to severe eczema.