� � Posted before Dec-31-2007
Our skin is a great regulator of temperature and aids in normalizing the body temperature whenever it goes up or dips. For instance, our body temperature shoots up when we are suffering from fever or we are vigorously working physically and we begin to sweat, often profusely. In fact, the process of sweating is basically a way by which our body endeavors to lower the temperature.
In addition, our skin also shields us from all injurious materials going into our body by the process of eradicating numerous contaminants from our system. By doing so, the skin helps in reducing the workload of the kidneys and liver as well as continuously straining out the by-products or undesirable elements produced during the metabolism process in the body. Most importantly, did you know that our skin also respires?
Most people are aware of the fact that the skin is the first line of protection against all kinds of harmful factors - microorganisms, contaminants and wind. In addition, our skin is also an acid mantle or shroud as a delicate film with a faintly acidic pH on the exterior of the skin offers valuable fortification of the skin. As an integral part of the impediment utility of the stratum corneum, our skin has an extremely vital responsibility. Latest researches have shown that enhanced enzyme actions of phospholipase A2 (PLA2s) - upstream regulators of many inflammatory processes, is associated with the development of the acid mantle in the stratum corneum. Such an arrangement makes our skin less porous to water as well as other polar compounds (compounds whose electrons are not shared equally in chemical bonds). In fact, this combination is also a part of the cause behind the low pH of the skin's exterior. In healthy people, the normal skin surface pH is something between 4 and 6.5. However, this usually differs at dissimilar areas of the skin's surface.
Compared to grown up people, newborn infants certainly have a higher skin surface pH, but this is put on a normal footing within three days of their birth. It is very essential to protect the stratum corneum for reasons that if it is harmed, the skin surface pH normally tends to increase making the skin vulnerable to bacterial contagions on the skin surface or damage of the skin and other ailments.
Nevertheless, we begin to produce more hair on our body during puberty. The hair follicles or cells possess related sebaceous glands (microscopic glands in the skin that secrete an oily/waxy substance called sebum) that turn out to be more vigorous as the growth of hair enhances resulting in alterations in the skin surface's pH. In addition, the hormones that regulate sweating also happen to be on the go and the entire surface of a teenager's skin is completely dissimilar to the skin exterior of a little kid. Actually, this is one of the ways by which our body augments its resistance structure to fight harmful elements.
As mentioned earlier, the normal skin surface pH of an average and healthy person is anything between 4.5 and 6. All the same, it differs with age as well as in different skin areas. Usually, newborn babies have a skin surface pH that is around neutral, approximately pH 7. This becomes acidic swiftly so as to protect the skin of little children from any kind of harm - externally or from within.
During the period between the late teens and early 20s of one's life, the acid mantle or coverage on the skin surface is properly developed and offers an excellent fortification against all potentially injurious and external ecological aspects. It needs to be mentioned here that our skin normally appears healthy and restores to its health rapidly whenever harmed. In a nutshell, it looks as if our skin is able to look after itself in all respects.
Nevertheless, with advancing age, the skin surface pH turns out to be increasingly neutral and, therefore, becomes more vulnerable to bacterial infections and growth. The diminished acidic coverage is able to eliminate a lesser bacteria compared to what it could do earlier. As a result, the skin becomes more vulnerable to bacterial infections and growth of harmful microorganisms. Consequently, the skin grows weaker and starts developing various problems with increasing age. It may be noted here that when a person actually experiences any skin problem or skin ailment, his or her skin surface pH has risen beyond 6!
With the advancing age biochemical modifications occur in collagen and elastin, the two connective tissues lying just beneath the surface of the skin. While collagen provides firmness to the skin, elastin gives it suppleness. Hence, with the aging process, the skin begins to lose some of its firmness and elasticity. However, the proportion of loss of the skin's firmness and elasticity usually varies from one person to another primarily based on their respective genetic structure, general health conditions, excessive exposure to the sun, skin care management or the absence of any skin care and several other aspects.
As the skin becomes less supple, it also turns out to be drier causing the fatty tissues lying beneath the surface layer of the skin to disappear. As a result, the skin begins to sag or hang down. When the skin losses its elasticity or suppleness, wrinkles, crow's feet and other fine line begin to appear on the skin, especially in the facial region. During this phase, our skin becomes extremely vulnerable to injuries as well as infections and repairs more slowly. At the same time, the skin's surface is inclined to dry out faster than before.
As discussed earlier, the acid mantle or covering on the surface of the skin saves it from all harms, including bacterial and fungal contagions as well as other ailments. The acid mantle is comprised of lactic acid and a variety of amino acids from sweat, amino acid and pyrrolidine carboxylic acid from the cornification process (the process of forming an epidermal barrier in stratified squamous epithelial tissue) of the skin as well as free fatty acids from sebum.
The acid mantle
The acid mantle or covering on the skin surface performs a number of tasks with the objective of protecting our skin from infections and diseases. Below are some of the basic functions of the acid mantle:
When the acid mantle is disturbed or injured or the covering loses its acidity, the skin becomes more susceptible to injuries and contagions. It may be mentioned here that excessive washing of the skin with soaps or detergents is likely to harm the acid mantle and result in its loss of acidity. In fact, recurring washing of the skin causes adverse changes the stratum corneum and the barrier functions, including destabilizing the skin surface pH. What is worse is that once the acid mantle is damages it takes around 14 hours to restore its health and in all probability by this time, the skin surface or the acid mantle may come under a fresh physical attack from another round of washing. It has been observed that on an average, most people wash their hands around thrice daily. It needs to be mentioned here that even a single washing of the hands is capable of shifting the skin surface pH to the alkaline region and it takes a few hours to normalize the pH again.
It has been found that a number of diseases are able to enhance the skin surface pH and this could be detrimental not only for the health of the skin, but our general well being too. Skin disorders that lead to an increase in the skin surface pH include eczema (a chronic recurring intensely itchy inflammation of the skin usually starting in early childhood), atopic dermatitis (an inflammatory, chronically relapsing, non-contagious and pruritic skin disease), dry skin and contact dermatitis (a delayed type of allergic reaction of the skin resulting from skin contact with a specific allergen, like poison ivy).
A severe eczema accompanied by wearing down is able to increase the skin surface pH from the normal to as high as 7.3 to 7.4. Since the skin surface pH is measured in logarithmic function, such a shift in the skin surface pH is considered to be a 1000-fold increase. In fact, the skin of people enduring atopic dermatitis has the entire skin surface pH increased. It may be mentioned here that any increase in the skin surface pH is a major factor for the colonization of Staphylococcus aureus (a bacterium responsible for difficult-to-treat infections in humans). In fact, Staphylococcus aureus possesses the aptitude to play a crucial role in the origin of atopic dermatitis, discoid eczema (nummular eczema) and infective dermatitis as a superantigen (disease-causing toxins).
Systemic diseases or ailments that involve numerous organs or the whole body that are capable of enhancing the skin surface pH include diabetes, chronic renal failure (persisting inability of the kidneys to excrete wastes) and cerebrovascular disease (a group of brain dysfunctions related to disease of the blood vessels supplying the brain).
Although scientists are yet to ascertain the reason behind the increased skin surface pH related to these diseases, it is presumed that they are associated with low intensity of phospholipase and owing to an involuntary malfunction that causes unusual secretion of sweat. It may be noted here that any increase in the skin surface pH leads to bacterial growths. In fact, diabetic patients have an augmented skin surface pH in the intertriginous areas (folds of the skin found around armpits, the groin, and knees). In addition, it is a well known fact that patients with diabetes are more vulnerable to Candida infections (contagions by yeasts), particularly in the intertriginous areas that usually remain moist most of the times. Several studies have demonstrated that Candidal skin injuries are more prominent on skins that have increased pH values. Scientists are of the view that this is possibly owing to a pH reliance of the yeast's aggressive capability and/ or an adjustment of the host protection aptitude.
It may be mentioned here that C. albicans (a form of yeast) possess two forms and pH, which is acidic by nature, prefers the blastospore variety. However, an enhanced skin surface pH favors the hyphael form. Actually, the hyphael variety of Candida is the original aggressor that thrives best at pH>6.5 and diabetic patients have a reduced level of skin lactic acid. Using skin occlusive (coagulum) products, for instance, dressings and diapers, are said to increase the skin surface pH and are related to skin contagions caused by C. albicans.
Broadly speaking, there are three major types of substances that function as skin cleansing agents.
Researches have demonstrated that compared to any synthetic detergent, soaps are responsible for turning the skin more alkaline. The potential of the cleansing agents, especially soaps and detergents, to give rise to skin irritation depends on several aspects, including skin surface pH. Here it may be mentioned that soaps generally raise the skin surface pH. In fact, compared to neutral or alkaline cleansing agents, the acidic disinfectants are less irritating to the skin. Hence, it is advisable that people who have dry skin should use acidic cleansers for the health of their skin. People who are at augmented risk for irritating skin reactions, it is always preferable to use cleansing agents that have somewhat acidic or neutral pH, such as nonionic surfactants. Hence, it is advisable that patients enduring skin disorders should always use a gentle cleansing agent that has a low pH. It is important to bear in mind that even a slight change in the pH of a skin cleansing product may prove to be significant as far as the integrity of the skin surface is concerned. This issue should be considered seriously while deciding to purchase the most favorable soap.