Lars Norlén
Dermatology Clinic, Department of Medicine and Department of Cell and Molecular Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden. E-mail: Lars.Norlen@ki.se
The very well-conducted pilot study by Alison Cooke et al. (p. XX) reported in the present issue of Acta Dermato-Venereologica evaluates, in biophysical terms, the effect on full-term neonatal skin of 4 weeks’ treatment with topical oils, and indirectly addresses the question as to whether the application of topical oils may contribute to the development of childhood atopic eczema. Both olive oil and sunflower oil contain significant amounts of unsaturated medium-chain fatty acids, which could potentially perturb the proper development of the skin’s barrier function in early childhood by disturbing the molecular organization of the lipid structure of the stratum corneum extracellular space. The study shows that the use of topical oils may increase hydration of baby skin, but, at the same time, raises the question as to whether the lipid structure of the skin barrier may concomitantly be altered. Support for the latter is given by the statistically significantly delayed improvement in lipid chain ordering post-stripping after 4 weeks’ treatment with olive oil (which has a high oleic acid content). However, such delayed improvement in lipid ordering was not observed after application of sunflower oil (which has a high linoleic acid content), and observed for olive oil at only 2 out of 3 measured locations (arm, abdomen and thigh). Furthermore, a statistically significant difference with respect to improvement in lipid ordering was not observed between olive oil and sunflower oil. The outcome is thus inconclusive, but hints at the possibility of a barrier perturbation in neonatal skin measurable by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. As such, this supports the call for a long-term observational study to investigate whether the application of topical oils from birth may contribute to the development of atopic eczema.
