Both lack of SC intercellular lipids and inadequate ratio between compounds (cholesterol, free fatty acids, ceramides) enhance transepidermal water loss leading to epidermal micro-fissuring.
Ceramide Deficiency On AD Skin
In AD, weak skin barrier is characterised by a lack of ceramide and other physiological lipids. Research demonstrated that ceramide is reduced by 30-50% in AD.3，4
3. Imokawa G et al. Decreased level of ceramides in stratum corneum of atopic dermatitis: an etiologic factor in atopic dry skin? J Invest Dermatol. 1991 Apr; 96(4):523-6.
4. Macheleidt O et al. Deficiency of epidermal protein-bound omegahydroxyceramides in atopic dermatitis. J Invest Dermatol. 2002 Jul;119(1):166-73.