A laboratory study that has received media attention suggests that aqueous cream may not be suitable for patients with eczema, due to its potential skin-thinning effect.

The authors note that aqueous cream is widely used to relieve skin dryness, however the formulation contains sodium lauryl sulphate (SLS), a known skin irritant. They carried out a study on six volunteers to investigate the effects of aqueous cream on skin barrier function and its effect on the stratum corneum (SC).

Each volunteer applied aqueous cream twice daily to one side of each forearm, the other side being used as untreated control. After four weeks, tape stripping and transepidermal water loss (TEWL) measurements were made. Outcomes were changes in SC thickness, baseline TEWL and rate of increase in TEWL during tape stripping.

Results in 16 out of 27 treated skin sites showed reduced SC thickness (mean decrease 12%; P = 0.0015) and an increase in baseline TEWL (20%; P < 0.0001), as well as a faster rate of increase in TEWL during tape stripping.

The authors conclude that “application of Aqueous Cream BP, containing about 1% SLS, reduced the SC thickness of healthy skin and increased its permeability to water loss. These observations call into question the continued use of this emollient on the already compromised barrier of eczematous skin.”

[Editor’s comment: a laboratory study in a small number of volunteers, so some caution is needed in interpretation; nevertheless, aqueous cream is not recommended in this condition by NICE guidance and this study supports that recommendation.]