The Anatomy And Physiology Of Dry Skin

The term dry skin is the expression of the skin that has a rough, dry or scaly appearance with the possible presence of reddening, cracking, or itching [3]. Dry skin can be due to sun damage, immature cells in the surface of the skin as in psoriais or the genetic changes in the desquamation process, as in atopic dermatitis. In all of these cases, a loss of moisture in the surface corneocytes or intercellular lipids results in an outer stratum corneum layer that is mechanically less pliable. Reducing flexibility result in cracking and changes of the outer layer, propagating cracks through the stratum corneum barrier. The normal flexing of the damaged skin that has little flexibility increases scaling and cracking [4]. Later, this dry skin can develop irregular erythematous lines.

At first, the hands, lower legs and dorsal forearms are affected with dry skin [3]. Although the dry skin is not a life-threatening subject, but it's unpleasant symptoms can reduce the quality of life [5].

To better explain the complexities of dry skin, external factors which may actually induce dry skin must be considered. First, you must consider the physiology of the stratum corneum layer that is individual keratinocytes joined by complex lipid bilayers. The protein lipid matrix within the keratinocyte needs moisture to be flexible. Lack of moisture in the matrix makes stratum corneum to become stiff and nonpliable, therefore, during the cold, dry weather, microscopic mechanical cracks in the skin created [4]. Factors such as cold weather or low humidity decrease the water content of stratum corneum. In addition to these factors, exposure to wind and ultraviolet radiation of the sun can affect normal skin's barrier