Characterisation of dry skin in vitro and in vivo in a paediatric population

Although child dry skin is very common, there are only few or no data available about the mechanisms driving this condition. Knowledge of baby and child dry skin could be of great interest in order to develop appropriate skin care.
A study has been conducted on 80 subjects with normal or dry skin (40 children each), aged from 1 day to 4 years (4 age groups). Biological samples have been collected on the forearms using swab in order to perform NMF and ceramides quantification.
Results show that skin maturation process after birth was similar in normal and dry skin. However, some key differences were noted: NMFs and ceramides were significantly reduced in dry skin for each age group, including newborns, with the lowest concentration reached at 4/6 months.
Based on these results, we designed and characterized an in vitro model of child dry skin by incubating 1 year-aged reconstructed epidermis in a dry environment (25% relative humidity). Analysis of ceramides showed a significant decrease in this model, which correlated with our in vivo observations. Moreover, qPCR analysis showed an inhibition of stem cells markers in our dry skin model suggesting that dry skin condition might impair cell pools in child skin.
Noninvasive in vivo skin investigation combined with in vitro child skin models is a good approach to study dry skin in a pediatric population and consequently to drive cosmetic research. This approach revealed that skin dryness represents a real skin type starting from the first days of life.

Ms Gaelle Bellemere