When the skin loses moisture and lipids, the natural barrier crumbles. Dry ambient air may favor this process, if the body itself can no longer obtain enough from inside to compensate. This can be the case in sick or older people especially. The same goes for infants whose skin is not yet fully formed.
In these cases, the corneal layer becomes increasingly porous and loses its protective function more and more. At the same time, dangerous substances can penetrate more easily which leads to skin irritations and inflammations.
Healthy skin protects against cold, heat and radiation, and keeps germs and microorganisms away with a slightly acidic pH value of 5.7. The skin is also our largest sensory organ, supports breathing and cools the body with sweat.
All in all, the skin is multi-functional, combines water and fat tissues and provides an external barrier.