earticle

영어

Atopic dermatitis (AD) is an itchy inflammatory dermatitis with a chronic course with remissions
and exacerbations. AD occurs primarily in children, but persisting cases in adulthood as well as
adult late-onset AD occur. Usually the personal and/or family history of other atopic conditions,
such as asthma and allergic rhinitis, are positive. It is estimated that about 20% of the population
of the industrialized countries has an atopic constitution, and between 5 and 20% suffers at least
during some period of their life from AD. Treatment of AD is largely confined to the application of
anti-inflammatory drugs such as corticosteroids; calcineurin inhibitors are frequently prescribed as steroid sparing agents. The integrity of the skin barrier, in particular the composition of the
stratum corneum, appears to be of great importance for the development and progression of skin
lesions in patients with AD. Optimal barrier function requires the presence of sufficient
extracellular lipids to form a competent lamellar bilayer system. The barrier abnormality in AD
correlates with a global reduction in these stratum corneum (SC) lipids, along with a selective
reduction in 1 of the 3 key species, the ceramide fraction. Yet current water-in-oil emollients and
moisturizers, though considered mainstays in the symptomatic management of AD, neither address nor correct the underlying SC lipid abnormality. Moreover, improperly formulated emollients and moisturizers can aggravate permeability barrier abnormalities, and therefore, in theory, they could both sustain preexisting disease and exacerbate previously quiescent dermatoses. One of the vital functions of the stratum corneum, the outermost layer of the skin, is known to provide a barrier against water loss through the skin. The effective barrier function of stratum corneum has been attributed to a highly ordered structure of lipid bilayers observed in the intercellular space of stratum corneum. In this study, we investigated the barrier function of a lamellar structure which is similar to the lipid bilayers in the skin. To prepare lamellar structures which are made up pseudo ceramide PC104, stearic acid and cholesterol, the thermotropic properties and the structural characteristics of ceramide PC104/stearic acid/cholesterol were studied by differential scanning calorimetry(DSC) and X-ray diffraction. A mixture of ceramide PC104, stearic acid and cholesterol was in a stable α-form having a lamellar structure. Also, stearic acid was found to be able to stabilize the lamellar structure of ceramide PC104. Moisturizers are widely recommended and used in AD, and when their use is encouraged by nursing assistants, they greatly reduce topical steroid usage. Many studies showed that “skin physiological lipid mixture” is effective for accelerating barrier recovery. But there are some requirements to accelerate barrier recovery with the inclusion of lipid mixture to moisturizing product. It is well documented that the adequate molar ratio of lipids is important for barrier recovery. Unless a substantial dose is provide, the lipid mixture cannot achieve barrier recovery for AD. And the free fatty acid component should comprise predominantly which are of sufficient length to interact within the lamellar membrane system. We developed pseudoceramide (PC-104) dominant, physiologic lamella structure base (DermaONTM) from above rationale and assessed the efficacy of the product with it on barrierdisrupted and Atopic skins.