Skin Physiology, Irritants, Dry Skin and Moisturizers
皮膚生理學，刺激物，皮膚乾燥，保濕劑
Christina Marino, MD, MPH Report Number 56-2-2001a August 2001 (Revised June
2006)
Washington State Department of Labor and Industries Safety and Health
Assessment and Research for Prevention Program http://www.lni.wa.gov/Safety/Research/Dermatitis/
1-888-66-SHARP 1-888-66-SHARP
克里斯蒂娜馬里諾，醫學博士，公共衛生報告編號56-
2- 2001a
2001年8月（2006年6月修訂）
華盛頓州 勞動和行業的安全和健康評估和預防方案的研究
Skin is a physical barrier to the environment. It is the alteration of the
barrier properties and actual damage to this barrier that causes dryness and
dermatitis when the skin is exposed to water, soaps, gloves, chemicals and harsh
weather conditions. The repair of the damage by moisturizers is related to the
physical and chemical interactions of the ingredients with the natural skin
barrier.
皮膚對於外界環境為一種物理性屏障。
當皮膚接觸到水，肥皂，手套，化學品和惡劣的天氣狀況，造成屏障性質的改變和實質損害發生時，會導致乾燥和發炎。 此可經由保濕劑與天然皮膚屏障中的成分產生物理和化學的相互作用來修復損害。
Skin Physiology: Structure and Function Basics
皮膚生理學:
結構和基本功能
Skin has two main structural layers—the
epidermis and the dermis (Figure
1).
皮膚有兩個主要的結構層的表皮和真皮（圖 1）。
‧ The epidermis is the outer layer
of skin, which serves as the physical and chemical barrier to the interior body
and exterior environment.
‧表皮是皮膚的外層，作為身體內與外部環境間的物理和化學屏障。
‧ The dermis is the deeper layer providing the structural support of the
skin.
‧真皮為深層皮膚，提供皮膚的結構支撐。
皮膚是人體最大的器官，由皮層之間的分裂細胞組成，當中包括Corneocytes、Fibroblast及Melanocyte等。Corneocytes組成表皮層，並演化成角質層來保護皮膚，控制皮膚質地及光澤度；Fibroblast則負責製造膠原蛋白、彈力蛋白及細胞間質等，為皮膚提供承托力和彈性，影響肌膚彈性紋理；而Melanocyte就能釋放適當的黑色素防止紫外線傷害皮膚，控制膚色。
Epidermis and Stratum Corneum: The Structure and Growth of
Skin
表皮和角質層: 皮膚的結構和生長
The epidermis consists of stacked layers of cells in transition. Protein
bridges called desmosomes connect the
cells.
表皮由逐漸轉型的細胞層層堆疊組成。藉蛋白質橋樑稱為胞橋小體(Desmosome)來連接細胞。
‧ The bottom layer of cells adjacent to the dermis are the basal cells which reproduce.
‧表皮最底一層是基底細胞，與真皮細胞相鄰，負責製造表皮細胞。
‧ As the cells mature, they move towards the outer layer of skin leading to
terminal differentiation of the cells. During the process of maturation, the
physiology, chemical composition, shape and orientation of the cells change.
‧表皮細胞的逐漸成熟，會往外層移動，最後成為無生命的角質細胞層。在成熟過程，細胞發生生理，化學組成，形狀和方向的變化。
‧ When the cells reach the top layer of skin—the stratum corneum—the cells are called and are
no longer viable. Corneocytes lack a nucleus and cellular structures.
‧當細胞到達皮膚頂層，形成角質層（stratum
corneum），不再分化。角質細胞（corneocytes）缺乏細胞核和細胞結構。
‧ Corneocytes are flat,
hexagonal-shaped cells filled with water-retaining keratin proteins surrounded by a protein
envelope and lipids (Figure 2). The cellular shape and the orientation of the
keratin proteins add strength to the stratum corneum. There are 10-30 layers of
stacked corneocytes.
‧角質細胞呈扁平六角形，被含水的角質蛋白所充滿，周圍環繞蛋白質外套和脂質（圖 2）。角質層由10-30層的角質細胞所堆疊。細胞的形狀和角質蛋白的方向築起角質層的力量。
‧ The thicker skin on the palms and soles has the most layers of stacked
corneocytes.
‧手掌和腳掌的皮膚較厚，因為有最多層堆疊的角質細胞。
‧ The cells remain connected to each other by protein bridges called
desmosomes. Stacked bilayers of lipids
surround the cells in the extracellular space. The resulting structure is the
natural physical and water-retaining barrier of the skin.
‧細胞間仍然靠著胞橋小體為橋樑彼此相連。角質細胞被細胞外空間堆疊的雙層脂質膜所包圍。此結構是皮膚的自然物理保水屏障。
Filaggrin： The Breakdown of Skin
聚角蛋白微絲：皮膚損傷
聚角蛋白微絲(Filaggrin)是皮膚角質層中一種不可或缺的蛋白質。如果這種蛋白因為遺傳缺陷而減少或缺乏，自然的角質化（cornification）受到妨礙且皮膚的自然屏障功能也會受限。
環境污染或肥皂的使用、中央空調可能刺激或使皮膚乾燥。皮膚的保溼、減少刺激過敏物很重要。
During the process of maturation, the viable cells moving towards the stratum
corneum begin to clump proteins into granules.
在表皮細胞的成熟過程中，當發育活細胞移向角質層時，聚集蛋白進入顆粒層。
‧ These granules are present in the granular cell layer of the skin and are
filled with a protein called filaggrin.
‧這些顆粒存在於皮膚顆粒細胞層和顆粒內充滿一種稱為聚角蛋白微絲（filaggrin）的蛋白質。
‧ Filaggrin becomes complexed with keratin proteins in the granular cells.
This complex protects filaggrin from proteolytic breakdown.
‧顆粒細胞的聚角蛋白微絲與角質蛋白複合在一起。這種複合物能保護聚角蛋白微絲不被蛋白酶分解。
‧ As the degenerating cells move towards the outer layer of the skin, enzymes
break down the keratin-filaggrin complex.
‧當逐漸退化的細胞往皮膚最外層移動，酶就會將角蛋白-聚角蛋白微絲複合物分解。
‧ Filaggrin is on the outside of the corneoctyes and water-retaining keratin
remains inside the corneocytes of the stratum corneum.
‧聚角蛋白微絲位於角質層的角化細胞外面，而保水的角蛋白則保持在角化細胞的裡面。
When the moisture content of the skin is decreased, specific proteolytic
enzymes in the stratum corneum are triggered to further break down filaggrin
into free amino acids.
當皮膚的含水量下降，觸發角質層中特定的蛋白水解酶，進一步分解聚角蛋白微絲成游離氨基酸。
Natural Moisturizing Factors: The Natural Retention of Water in the
Skin
天然保濕因子：讓水自然保留在皮膚中
The free amino acids, along with other physiological chemicals such as lactic acid,
urea and salts, are present in the
stratum corneum.
游離氨基酸，連同其他存在於角質層的生理化學物質，如乳酸，尿素和鹽。
大約一半是氨基酸成分，另外一半則是一些鹽類或電解質成分，像是乳酸鹽、尿素、PCA鈉鹽等，這些天然保濕因子可以將水分留住，增加表皮淺層的水分含量。
‧ Together these chemicals are called “natural moisturizing factors” and are
responsible for keeping the skin moist and pliable by attracting and holding
water—a property called hygroscopic.
‧這些化學物質被稱為“天然保濕因子”，負責吸引和保住水分，保持皮膚的濕潤和柔軟，此特性稱為吸濕性（hygroscopic）。
‧ The water content of the stratum corneum is normally about 30%.
‧角質層的水分含量正常約30％左右。
‧ The proteolytic breakdown of filaggrin to amino acids only happens when the
skin is dry to control the osmotic pressure of the skin and the amount of water
it holds. There is less need for breakdown of filaggrin in humid weather than in
dry weather.
‧聚角蛋白微絲被分解成氨基酸，只會發生在乾燥的皮膚，利用保水的多少來調滲透壓。所以在潮濕的天氣比乾燥的天氣較不需要聚角蛋白微絲的解離。
Generation of Natural Moisturizing Factors in the
Skin
皮膚的自然保濕因子的生成
Maturation and differentiation of epidermal cells in the middle layer of skin
皮膚中間層的表皮細胞成熟和分化
↓
Filaggrin protein clumps into granules in the
granular cell layer
聚角蛋白微絲蛋白成團塊的進入顆粒細胞層的顆粒
↓
Filaggrin becomes
complexed to keratin protein to protect from proteolytic degradation
聚角蛋白微絲與角蛋白形成複合物，以避免蛋白酶的降解
↓
Cells lose their normal cell contents and
become protein envelopes filled with keratin/filaggrin proteins called
corneocytes
活細胞失去正常的內容，只有充滿角蛋白/聚角蛋白微絲蛋白的蛋白質包囊稱為角質細胞（Corneocytes）
↓
Corneocytes move towards the very outer layer skin
角質細胞朝皮膚的最外層移動
↓
Enzymes break down keratin/filaggrin complex to filaggrin and keratin
酶將聚角蛋白微絲-角蛋白複合物解離
↓
Decreased water content stratum corneum
當角質層水分含量降低時
↓
Proteolytic enzymes activated
蛋白水解酶被激活
↓
Filaggrin degraded into individual amino acids
聚角蛋白微絲降解成個別氨基酸
↓
Amino acids plus other chemicals form Natural Moisturizing Factors in
stratum corneum
氨基酸在角質層與其他化學物形成自然保濕因子
↓
Holds water to rehydrate
stratum corneum
捉住水來補充角質層水分
Desquamation (The Shedding of Skin Cells)
脫屑（皮膚細胞的脫落）
Desquamation is another important factor in keeping the skin
smooth.
脫屑是保持皮膚光滑的另一個重要因素。
‧ Desquamation is the enzymatic process of dissolving the desmosomes, the
protein connections between corneocytes, and the eventual shedding of these
cells.
脫屑是酶將角質細胞間做為連接的胞橋小體(Desmosome)溶解，造成這些細胞脫落過程。
人類不同皮膚部位的角質層細胞之脂肪膜狀結構，是表皮滲透性障壁(Epidermal permeability barrier:
EPB)差異之原因。
人類掌蹠部位(全身EPB功能最差之處)之脂肪膜狀結構數量遠低於顏面，於顏面部位，平行脂肪膜主要是由3及6條所構成，而掌蹠部位則由2及4條所構成，至於胞橋小體(Desmosome)之數量，掌蹠部位則遠高於顏面(20%以下)，約佔整體角質細胞間隙之50-60%；以上形態學上之觀察顯示脂肪膜狀結構數量的多寡與EPB功能有極密切之關係，並可解釋何以掌蹠部位EPB功能劣於身體它處。
‧ Opposite to the production of amino acids from proteolytic degradation of
filaggrin proteins, the proteolytic enzymes responsible for desquamation
function in the presence of a well-hydrated stratum corneum. These enzymes are
located intercellularly.
‧聚角蛋白微絲蛋白降解產生氨基酸，負責脫屑功能的蛋白水解酶需要在一個良好的水合角質層中才能發揮。這些酶是位於細胞之間。
‧ In the absence of water, the cells do not desquamate normally and the
result is thickened, dry, rough, scaly skin.
‧在缺水的情況下，細胞不能正常脫皮，結果是變厚，乾燥，粗糙，鱗狀皮膚。
‧ There is a normal physiological balance in the production of corneoctyes
and shedding. Increased production of corneocytes (skin diseases such as
psoriasis) or decreased shedding (skin diseases like ichthyosis) results in the
accumulation of cells on the skin surface and dry, rough skin.
‧角質細胞製造和脫落是一種正常的的生理平衡。角化細胞的製造增加（如牛皮癬）或脫落減少（魚鱗癬），結果是過多的細胞細胞積累在皮膚表面造成乾燥和粗糙。
Desquamation of Cells
細胞脫屑
Intact
corneocytes in upper level of hydrated stratum corneum
完整的角質細胞在含水的角質層上層
↓
Proteolytic enzymes break protein connections between corneocytes
蛋白水解酶打斷角質細胞之間的蛋白質連接
↓
Corneocytes desquamate
角質細胞脫皮
↓
Skin
stays normal without dry scales
皮膚保持正常濕度
Intercellular Lipids
細胞間脂質
The last factor that is necessary in explaining how the natural skin barrier
works to keep the skin moist and pliable is the function of the intercellular
lipids.
保持皮膚濕潤和柔軟的自然屏障工程中的最後一個因素是細胞間脂質的功勞。
‧ These lipids form stacked bilayers (multilamellae) surrounding the
corneocytes in the stratum corneum and incorporate water into this architecture
(Figure 3).
‧在角質層的角化細胞周圍，這些脂質雙層堆疊形成多層，並將水納入這個結構（圖 3）。
‧ The lipids are derived from the degradation of cells in the granular layer
of skin (similar to the origin of the protein granules). Special lipid
structures called lamellar granules are released into the extracellular spaces
of the degrading cells. There is also release of lipids from the former cell
membranes.
‧脂質來自皮膚顆粒層細胞的退化（類似的蛋白質顆粒的來源）。稱為層狀顆粒（lamellar
granules）的特別脂質結構被釋放到退化細胞外空間。也有從退化細胞細胞膜釋放的脂質。
‧ These released lipids include
cholesterol, free fatty acids and
sphingolipids.
‧這些釋放的脂類包括膽固醇，游離脂肪酸和鞘脂。
‧ Ceramide, a type of sphingolipid derived from the lamellar granules, is one
of the major lipid components responsible for generating the stacked lipid
structures. These lipids trap water molecules in their hydrophilic (water
attracting) region.
‧神經醯胺，來自層狀顆粒的鞘脂，是負責產生堆疊的脂質結構的主要脂質成分之一。這些脂質利用其親水端（水吸引）來捕捉水分子。
‧ The newly formed stacked lipids surrounding the corneocytes provide an
impermeable barrier for the passage of water out of the stratum corneum and the
prevention of the natural moisturizing factors from leaching out of the surface
layers of skin.
‧新生成的堆疊脂質圍繞的角化細胞，提供角質層防水滲出的屏障，預防天然保濕因子溢出皮表。
‧ There are sharp decreases in intercellular lipids after age 40 resulting in
more susceptibility to dry skin conditions.
‧40歲以後細胞間脂質急劇減少，更易導致皮膚乾燥狀況。
Intercellular Lipid Layers
細胞間脂質層
Lipids in granular cell layer of skin form granules
脂質在皮膚顆粒細胞層形成顆粒
↓
Degeneration of granular cells releases lipid granules into intercellular
spaces
顆粒細胞變性，釋放脂質顆粒到細胞間隙
↓
Lipids released from degeneration of
cells and lipid granules complex together to form intercellular stacked lipid
structures
脂質從細胞變性釋出，脂質顆粒複合體聚集形成細胞間堆疊的脂質結構
↓
Lipid layers hold water
and surround corneocytes to provide permeability barrier
環繞角質細胞的脂質層捉住水，提供通透屏障
The intercellular lipids and corneocytes containing proteins and natural
moisturizing factors work together to provide an efficient barrier against water
loss and water retention to maintain the flexibility of the skin. The protective
forces shield the skin from desiccation and environmental assaults.
細胞間的脂質和含有蛋白質和天然保濕因子的角質細胞共同提供有效的屏障，有效的對抗水分的流失，保持皮膚的彈性。保護力量免於皮膚乾燥和環境的攻擊。
Irritants and Damage to the Skin Barrier
刺激物和破壞皮膚的屏障
The major factor responsible for dry, scaly skin and irritant dermatitis can
be related to the loss of water from the stratum corneum.
乾燥，鱗屑和刺激性皮炎的主要因素，與角質層脫水有關。
‧ This loss of water is called transepidermal
water loss (TEWL).
‧這種水的損失，即所謂的經皮水分流失（TEWL）。
‧ The stratum corneum receives water from the dermis and some from the
environment.
‧角質層的水來自真皮層和一些來自環境的水。
‧ Water is the “plasticizer” of the skin making it pliable and smooth.
‧水是皮膚的“增塑劑”，使其柔韌並平滑。
‧ Numerous external factors can cause TEWL.
‧許多外部因素可能會導致經皮水分流失。
‧ The water content of the stratum corneum fluctuates with environmental
humidity levels. There is accentuation of dry skin with exposure to cold, wind
and low humidity.
‧角質層的水分含量隨環境的濕度而波動。 皮膚會暴露在寒冷，風吹和低濕度下而加重乾燥。
‧ Other external factors damage the stratum corneum barrier by denaturing
keratin protein, removing natural moisturizing factors and interrupting the
lipid bilayers. These factors include solvents, detergents, excessive use of
water and soap, and other irritating chemicals.
‧其他外部因素損壞角質層屏障，包括角質蛋白的變性，天然保濕因子的消失和雙層脂質的中斷。這些因素包括溶劑，清潔劑，過度使用水和肥皂，和其他刺激性化學品。
‧ The severity of the damage is dependent on the type and intensity of
exposure to these irritating factors.
‧損傷的嚴重程度取決於接觸到這些刺激因素的類型和強度。
An irritant is any agent that is capable of producing cell damage if there is
exposure for sufficient time and in sufficient concentrations.
‧任何刺激物，如果有足夠的時間和足夠的濃度，就能夠產生細胞損傷。
‧ It may require repeated and prolonged exposure to see the actual damage.
‧肉眼看到的實際損失，可能需要反覆和長時間的接觸。
‧ Anyone exposed to excessive amounts of cleaning agents and water--health
care personnel, hairdressers, food service workers, bartenders, and
dishwashers--may experience extreme changes in the health and nature of their
skin.
‧任何人都暴露在過量的清潔劑和水 - 醫護人員，理髮店，餐飲服務人員，調酒師，和洗碗工 - 可能有遇到皮膚健康性質極端變化的經驗。
Water is a weak irritant.
水是一種弱刺激物
‧ Significant water exposure causes the loss of the soluble natural
moisturizing factors and some of the protective lipids paradoxically resulting
in TEWL.
‧大量的水接觸，造成可溶性天然保濕因子和脂質的流失。
‧ Persistent hydration of the skin from exposure to water results in:
‧皮膚持續浸潤水中導致：
o Penetration of foreign substances and contribute to allergic and irritant
contact dermatitis and
Ø外來物質的滲透和造成過敏性和刺激性接觸性皮炎
o Changes in the normal ecological environment in/on the skin, which can
support the overgrowth of pathological organisms on the skin.
O皮膚在正常生態環境的改變，導致致病生物的過度生長。
Soaps and cleansers are considered mild irritants.
肥皂和清潔劑被認為是溫和的刺激物
‧ These agents are beneficial surfactants that remove exogenous dirt,
bacteria, skin oils, perspiration and crusts (desquamated skin cells).
‧這些清潔劑為界面活性劑有利於去除外表污垢，細菌，皮膚油脂，汗液和結痂 （脫落的皮膚細胞）。
‧ Repeated and prolonged exposure to these cleansers results in denatured
skin proteins, disorganization of the lipid lamellae layers, removal of the
protective intercellular lipids, loss of natural moisturizing factors and
decreased cohesion between cells.
‧反復和長時間接觸這些清潔劑的結果，導致皮膚蛋白質變性，片狀層脂質解體，保護細胞間的脂質移除，天然保濕因子流失和細胞之間的凝聚力下降。
‧ The temperature of the water can increase the irritant capacity of skin
cleansers by causing increased absorption of the cleanser with warmer
temperatures. There is greater removal of the protective lipids with hotter
water.
‧溫水可以導致皮膚對潔膚劑的吸收增加。造成更多防護性油脂的移除。
‧ The end result of prolonged use of water and cleansing agents is alteration
of the water-holding capacity of the skin and an increased TEWL. Dry, scaly skin
that is less pliable and damaged is the physical result.
‧長時間使用水和清潔劑的最終結果是改變皮膚的保水能力和增加經皮水分流失。乾燥，鱗屑、少柔韌性和損壞的物理結果。
There are also endogenous factors that make one more susceptible to damaged
skin by external factors.
也有內源性因素，使一個受損的皮膚對外部因素更敏感。
‧ These factors include having active skin disease such as psoriasis, eczema,
inherited dry skin conditions (ichthyosis), a previous history of skin diseases
(childhood eczema), sensitive skin and/or older age.
‧這些因素包括急性期的皮膚疾病，如牛皮癬，濕疹，遺傳性皮膚乾燥狀況（魚鱗），以前的皮膚疾病（兒童濕疹），敏感的皮膚和/或老年人。
‧ These endogenous factors may exacerbate dryness of the skin and increase
one’s susceptibility to dermatitis.
‧這些內生性因素可能會加劇皮膚乾燥和皮炎的易感性增加。
In summary, the exposure to irritants with the resulting transepidermal water
loss compromises the barrier function of the stratum corneum and decreases its
ability to protect the skin against environmental influences.
總之，暴露於刺激物與經皮水分流失危及角質層的屏障功能，並降低皮膚對環境影響的保護的能力。
‧ The harsher the cleansers or solvents, and/or prolonged exposure to
irritants, the greater removal of protective lipids, proteins, natural
moisturizing factors and water loss.
‧更嚴厲的清潔劑或溶劑，和/或長期暴露於刺激物，保護的脂類，蛋白質，天然保濕因子和水分會流失更多。
‧ With decreased water capacity, there is also loss of function of the normal
enzymes to desquamate the corneocytes.
‧水能力下降，也導致角質細胞失去正常的酶的脫皮功能。
‧ If the water content of the skin is less than 10%, these interacting
factors are disturbed and the result is dry, scaly, fissured and less pliable
skin.
‧如果皮膚的含水量小於
10％，這些相互作用的因素被干擾，結果是乾燥，鱗屑，龜裂和皮膚柔韌性變差。
How Moisturizers Work
保濕工作
http://blog.yam.com/fanclaire/article/31946583
When the skin is damaged, repair is dependent on retarding the loss of
moisture from the skin.
當皮膚被破壞，修復依賴延緩皮膚水分的流失。
‧ Moisturizers are defined as chemicals that increase the water content of
the stratum corneum and are hydrating agents.
‧保濕被定義為化學物質的保濕劑，能增加角質層的含水量。
‧ Moisturizers work by using ingredients that are occlusive and/or humectant
agents.
‧保濕劑的成分效果為封閉性和/或潤濕保濕劑（吸濕劑）。
‧ These ingredients are the same or similar to natural components in the skin
(biomimetic).
‧這些成分相同或類似在皮膚內的天然成分（仿生）。
Occlusive agents work by physically blocking the
loss of water from the skin.
封閉性保濕劑作用為物理性阻擋水經皮水分流失。
‧ These hydrophobic agents form an occlusive film on the skin that reduces
TEWL by preventing evaporation of water from the stratum corneum.
‧這些在皮膚上的憎水劑，形成保水膜防止角質層水分的蒸發，降低經皮水分流失。
‧ These agents may also help to restore the lipid barrier of the skin.
‧這些保濕劑也可能有助於恢復皮膚的脂質屏障。
‧ Examples of occlusive agents include petrolatum, beeswax, lanolins and
oils.
‧封閉性保濕劑包括：凡士林，蜂蠟，羊脂和油。
Humectant agents attract water to the skin.
潤濕劑吸引水到皮膚。
‧ The water is drawn from the deeper dermis, rarely the environment.
‧水是來自更深的真皮層，很少來自環境。
‧ The hydration of the stratum corneum normalizes the intercellular lipids
and the natural desquamation process.
‧含水的角質層有助於細胞間脂質和天然脫屑過程的正常化。
‧ The skin becomes more resistant to drying conditions.
‧皮膚變得更耐乾燥條件。
‧ Humectants mimic the role of natural hydrophilic humectants in the stratum
corneum.
‧潤濕劑，模仿角質層的自然親水性保濕劑的角色。
‧ These chemicals include amino acids, lactic acids, alpha hydroxy acids,
propylene glycol, glycerine and urea.
‧這些化學物質包括氨基酸，乳酸，果酸，丙二醇，甘油和尿素。
‧ Some of these agents are the components of the skin’s natural moisturizing
factors.
‧製劑中有些是皮膚的天然保濕因子的組成部分。
“Barrier-repairing” moisturizers contain lipids that are similar to the
intercellular lipids of the skin. The combinations of fatty acids, ceramide and
cholesterol in the moisturizers may help to repair lipid bilayers affected by
soaps, solvents and extreme dry, cold weather conditions by replacing key lipid
components.
“屏障修復”的保濕劑包含脂類與皮膚細胞間脂質類似。脂肪酸，神經醯胺，膽固醇在保濕的組合，替代主要脂質成分，可以幫助修復脂質雙層，導因於肥皂，溶劑和極端乾冷的氣候狀況。
Moisturizers contain other ingredients besides humectants and/or occlusive
agents.
除了濕潤劑和/或封閉性保濕劑，保濕劑含有其他成分。
‧ Ingredients may improve the skin’s softness by lubricating and filling in
the spaces between dry skin cells. An ingredient list on a moisturizer will list
these agents as the “active” ingredients.
‧柔軟劑成分，可改善皮膚的柔軟性和填充乾燥的皮膚細胞之間的空間。
‧ The “inactive” ingredients solubilize, stabilize, emulsify, suspend and /or
disperse ingredients in order to produce an aesthetically pleasing product.
‧“無活性”的成分作用為溶解，穩定，乳化，懸浮和/或分散，以產生一個美觀的產品。
‧ Most moisturizers contain 65-85% water in a lotion form with water acting
as an agent to disperse the active and inactive ingredients. The high water
content also serves to allow absorption of some components and evaporation of
the moisturizer. The water acts as a temporary hydrating agent.
‧大多數保濕劑含有65-85％的水與水的乳液形式，作為代理人，以分散的活性和非活性成分。含水量高，可讓保濕的一些組件和蒸發吸收。水作為一個臨時的保濕劑。
‧ Moisturizers in a cream form contain less water and more oils or occlusive
agents.
‧保濕霜的形式為一包含較少的水和更多的油的霜劑或封閉性保濕劑。
‧ Ointments are oil-based compounds with a minimum amount or no water in the
product. These products are usually very occlusive and greasy. An example would
be pure petroleum jelly.
‧油膏產品為石油為基礎的化合物，含少許水或沒有水。這些產品通常都非常閉塞和油膩。一個例子是純凡士林。
Summary
摘要
The unique structure of the stratum corneum of the skin contributes to its
function as a barrier to water loss and the external harsh environment. The
injury to this barrier by the environment and common irritants with the
resulting loss of water from the skin is the main reason for the development of
dry skin or irritant dermatitis. Moisturizers can help to increase the hydration
of the skin and possibly repair/restore the barrier through use of chemicals
that are similar to the skin’s natural moisturizing factors or occlusion of the
skin to prevent water loss.
皮膚角質層的獨特結構，其功能為保水和外部惡劣環境的屏障。環境和刺激物損傷此屏障，引發水分流失是
皮膚乾燥或刺激性皮炎的發展的主要原因。保濕可以幫助增加皮膚的水合，並可能通過修理/恢復使用的化學物質，類似皮膚的天然保濕因子或閉塞的皮膚，防止水分流失的屏障。