Damage to the epidermis does not leave scars. Injuries that penetrate through to the dermis do however. The deeper the skin injury, the longer it takes for the skin barrier to be restored.
The renewal of the epidermis takes just fourteen days, but depending on the depth of the wound the increased trans-epidermal water loss (TEWL) may persist for 150 to 500 days.
While the epidermis is not functioning completely and the dermal remodelling is not completed, the barrier function of the renewed skin is problematic and needs special care in order to combat further water loss. This renewal process goes hand in hand with a dry, itchy skin that is much more sensitive and which is more easily penetrated by irritant substances, allergens and micro-organisms.