SKIN ANATOMY, CANCER, SCARS
Skin Anatomy & Physiology
When we speak of vital organs, we usually think of heart, lungs, and brain. When any stops functioning, we can't survive. Another vital organ, often overlooked, is our skin. We can't live without its protection.
Skin is the largest organ of the body, containing glands, blood vessels and nerves. Its first function is to serve as a barrier between our inner selves and atmospheric contaminants circulating in the outside world. When skin is cut, wounded, or even chapped, we are susceptible to invasion by bacteria, resulting in infection. No better case can be made for regular and appropriate cleansing of the skin. Cleansing in the morning rids the skin of the body waste materials that have accumulated during sleep. Cleansing again at night removes the collection of impurities from the atmosphere. The complexion should always be cleansed by emolliency, never soap, to guard against defatting and depletion of the barrier properties.
Skin is not impenetrable. It must allow for respirations, keeping the body temperature even. One square inch of skin may contain hundreds of sweat glands, thousands of nerve endings and receptors for perception of heat, cold, pain and tactile sensations. For these, among other reasons, skin creams must be non-comedogenic (non-pore clogging) to avoid a 'hot house' effect. Studies show that comedogenic products will cause unnecessary exertion of the body from obstruction of the respiratory process.
Even when it is totally unmarred, the skin is not a perfect barrier. For example, the drug scopolamine, used to fight motion sickness, can be introduced through a thin, plastic-like patch, placed behind the ear. This transdermal method of delivery can also be used for nitroglycerin given to heart patients. You don't get efficient absorption through the skin, but you get slow, constant absorption. This steady delivery means that the drug reaches a plateau in the body and stays there; unlike the highs and lows experienced when a drug is taken orally. Transdermal absorption is the only system of delivery available for topical skin care.
Resiliency and pliancy in the skin come from the stratum corneum; the top layer of skin. When skin is hydrated, it can move and stretch. When it's dry, it will crack. Despite the common advice to drink eight glasses of water a day, an excessive intake of fluids doesn't seem to help hydrate the skin or combat dryness.
SKIN ANATOMY, FUNCTION, PROTECTION
A. STRUCTURE OF SKIN
The skin is divided into three layers: the epidermis, the dermis, and the subcutaneous tissue.
Epidermis: contains five strata or layers. New cells are formed in the deepest of the five layers and are continually replaced. Replacement slows with aging and sun damage. Cells migrate upward to the most superficial layer (stratum corneum) where they are shed.
Dermis: Is divided into two layers. The thin papillary dermis (thin superficial layer) and the reticular dermis (deeper, thicker layer). The dermis contains three types of tissue: Collagen, elastin, and reticular fibers; blood vessels, which supply skin nutrition; and all nerve endings, which detect sensation and temperature.
Subcutaneous tissue: The fat tissue located deep to the dermis and superficial to underlying muscle.
B. FUNCTION OF THE SKIN
Skin is a barrier between our body and harsh foreign materials in our surroundings. It protects against bacteria and infection. Skin is responsible for regulating body temperature. Skin respiration and sweating maintain body temperature within acceptable limits. Skin contains most of our sensation receptors for heat, cold, pain, and tactile (touch) sensation. One square inch of skin contains thousands of nerve endings and receptors as well as hundreds of sweat glands.
C. DAMAGE TO THE SKIN
Ultraviolet Light Exposure
Types: There are three types of ultraviolet rays, UVA, UVB, and UVC. Only UVA and UVB penetrate the atmosphere. UVC is insignificant for sun exposure.
UVA: Intensifies the effects of UVB exposure, damages the collagen and elastin in the dermis, contributing to premature wrinkling and aging (photo aging.) UVA is the primary UV wavelength used in tanning booths. There is strong evidence that UVA exposure in the tanning industry is harmful to your health.
UVB: Causes genetic cell damage, which can lead to development of skin cancer. It also causes sunburns.
The idea that 'building a tan' prior to summer or vacation provides protection is a myth. Effects of sunlight exposure are cumulative and the more exposure, the more damage. That damage may not be evident for 10-20 years. Ultraviolet light can activate up to 40 different diseases, and has an adverse effect on the body's immune system. Photosensitivity reactions can occur with UV exposure. If you are taking any medications, check carefully about photosensitivity reactions that can occur with UV exposure.
Wind, Humidity, Temperature
Geographic Location: The nearer the equator (further south in the U.S.) the greater the intensity of UV exposure. At higher altitudes, UV exposure is also significantly greater.
Daily Activities: Activities outdoors increase UV exposure. Many recreational activities involve markedly increased exposure to UV, for example water sports or snow sports where reflection magnifies the exposure.
Examine your activities carefully. Even routine commuting outdoors involves sun exposure, the effects of which are cumulative over your lifetime. The relentless, cumulative every day exposure to ultraviolet radiation is much more dangerous than the occasional sunburn!
D. AGING OF THE SKIN (PHOTO AGING)
Many dermatologic experts feel that 90% of skin aging and wrinkling is due to ultraviolet radiation exposure. 80% of that exposure usually occurs before 20 years of age. UVA breaks down collagen and elastin in the dermis. This breakdown renders the skin more brittle and inelastic, contributing to dryness, cracking and disruption of skin integrity.
Generation of new cells in the deep layers of the dermis for cell replacement is slowed by UV exposure. Epidermal cell replacement also slows down with aging.
UV retards rate of cell production and blood vessel production.
- Loss of Lubrication
As dermal and epidermal sebaceous glands decrease production, the skin surface becomes drier, more brittle, and tends to crack and shed more cells.
- Loss of Elasticity (Development of Elastosis)
As the skin loses elasticity, normal movements of the skin with facial or body movement produce more direct stresses resulting in breakdown in the dermis rather than the normal response of stretching and rebounding.
- Stretching and Shape Distortion
If the skin does not 'give' with stretching and subsequently 'rebound', the stretching can result in breakdown of skin structures, and permanent shape or surface distortions. 'Stretch marks' and permanent skin laxity or looseness are examples of permanent shape distortion.
E. SKIN CANCER
Causes of Skin Cancer
- Ultraviolet Exposure
The most significant controllable factor in the development of skin cancer appears to be sun exposure.
Ultraviolet B (UVB) rays are most likely to cause genetic damage to cells, leading to skin cancer, but UVA may intensify UVB effects and therefore are also damaging.
- Inherited Predisposition
People who inherit the characteristics of fair skin and light colored eyes (e.g. people of Celtic origin) are most susceptible to damaging effects of UV radiation.
Costs of Skin Cancer
- The Defect
Skin cancers can result in loss of entire facial structures such as the nose, eyelid, ear or cheeks. The cancers usually develop later in life (after age 40), but can occur much earlier.
- Prices of Reconstruction
Although reconstructive techniques are available in modern plastic surgery, the procedures are expensive both monetarily, in time off work and emotionally
- Permanent Compromises.
Reconstructive surgery can never restore structures to their normal state.
When it is necessary to 'borrow' tissue from an area to reconstruct another area, donor site defects and scars result. Where the defect is reconstructed, scars and some contour irregularities usually persist. In severe cases, loss of body function can occur in addition to the cosmetic defect.
F. PRESERVING AND CARING FOR THE SKIN
Basic Skin Care
- Cleanse/Protect/Moisturize/Rejuvenate (i.e. Exfoliate, Improve Dermis, Control Pigment).
- Nutrition, regular exercise, vitamins supplements and holistic health principles are important concepts in maintaining general health as well as skin health. Healthy skin is beautiful skin.
- Sunscreens and Sunblockers
The most effective treatment for sun damage is prevention. Chemical absorbing sun screens as well as physical sunblockers must protect against UVA and UVB rays of the sun. They must give broad spectrum protection, and be well tolerated and compatible with various skin types. Shading and avoiding the most intense mid day sun complete the triad of sun protection that is so important in maintaining good skin health.
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Cancer of the skin effects upwards of one million Americans every year. One out of seven Americans will develop cancer of the skin in their lifetime. Ninety percent of all skin cancers are totally curable if taken care of early in their course. The three most common types of skin cancers are basal cell carcinoma, squamous cell carcinoma, and malignant melanoma.
Basal cell carcinoma is the most common and least serious of the three major types of skin cancer. This type of skin cancer frequently presents as a benign appearing lesion, which looks much like a pimple or smooth bump with shiny or raised edges. As it progresses, there can be crusting and intermittent bleeding from its surface.
Squamous cell skin cancer is the next most common type of skin cancer. It is more serious because it is a more aggressive cancer locally, and can spread to lymph nodes, and therefore vital organs. A squamous cell cancer is generally preceded by a pre-malignant lesion known as an actinic or solar keratosis. This keratosis is usually a slightly raised, rough, red patch, which may flake, itch, or bleed.
The deadliest form of skin cancer is a malignant melanoma. This type of skin cancer is the least common, but most dangerous variety. It will be discussed in more depth later in this overview.
As a general rule, the seriousness of a skin cancer is directly proportional to the aggressiveness of the tumor, both from the standpoint of local growth, and its potential for metastasis. Cancer metastases are defined as malignant cells which spread in the blood stream or lymph nodes to establish malignant colonies in other parts of the body. Vital organs are thus eventually destroyed and death ensues.
Symptoms that should alert one to the possibility of skin cancer are:
- A skin sore that does not heal, heals intermittently, or re-opens.
- A dry, scaly, red patch.
- A raised, waxy, or shiny bump.
- A wart or mole that changes in size, color, surface characteristics, elevation, or sensation (especially itching).
High-risk individuals include those of Celtic origin, i.e.: Ancestry north of the 45th parallel with fair skin, light colored eyes, red or blond hair, and freckles. Certain medical illnesses also predispose individuals to skin cancers; the most common being xeroderma pigmentosa, dysplastic nevus syndrome, basal cell nevus syndrome, nevus sebaceous and others.
Ninety percent of skin cancers are sun related. Their incidence is directly related to frequent, regular sun exposure, which causes cumulative effects on the skin. With this direct causal relationship, the most significant controllable factor appears to be limitation to sun exposure, i.e. exposure to ultraviolet (UV) rays. Ultraviolet rays of the sun cause cell injury in the skin. They damage epidermal and dermal cells causing genetic changes. They also weaken the body's general immunity to both skin cancers and other types of cancer. Ultraviolet rays also break down collagen and elastin in the deeper layers of the skin giving rise to premature aging (photo aging) and wrinkling of the skin.
Prevention of skin cancers by eliminating the common causative factors is obviously the ideal situation. However, early detection of skin cancer by regular exams certainly makes them more curable. Even though many skin cancers do not kill, they can, in advanced stages, produce significant disfigurement; for example, loss of a nose, an ear, or an eyelid to effect a cure. Significant scarring may result upon removal of large areas of cancerous growth on the head, face, and neck. Prevention through regular exams, and treatment of pre-malignant skin lesions early, especially actinic/solar keratosis, is strongly recommended.
Once established, skin cancers can be treated by a variety of common methods. Basal cell skin cancers are generally treated by electrodesiccation and curettage, cryotherapy, radiation therapy, or complete excision. Squamous cell cancers are treated by excision. Melanomas are treated by wide excision, lymph node dissection when indicated, and possibly chemotherapy and immunotherapy for more advanced cases.
Moh's micrographic surgery has the highest cure rate for basal cell and squamous cell skin cancers. It is not generally recommended for malignant melanoma, however. This is a highly specialized form of skin cancer removal that is used mostly for recurrent tumors, and tumors in difficult locations that generally have high recurrence rates. It is also indicated in critical facial regions such as the nose, ears, and eyelids, where the minimal amount of tissue to effect a cure should be removed, but no more. This is a critical consideration in regions of the face where reconstruction options are limited and complicated.
Alternative and more experimental methods for prevention and treatment for various types of skin cancers include dietary supplementation with high dose beta-carotene or vitamin C and E. These may be used as a preventative therapy in individuals with a prior history of skin cancer. Low dose retinoids, which are derivatives of vitamin A, are at times used as a preventative therapy both in regard to the development of skin cancer, and premature aging of the skin caused by actinic damage. In the treatment of malignant melanoma, various stimulants to the immune system have been attempted in advanced cases.
Malignant melanoma is the most dangerous form of skin cancer. This is due to the aggressiveness of the tumor and the high risk of metastatic disease. There are 23,000 new cases of malignant melanoma per year in the United States. The overall mortality rate at 5 years is 40 percent. There is a virtual epidemic in the rise of malignant melanoma. In 1930, Caucasian Americans had a lifetime risk of 1:1500. Today that risk is 1:150. Colorado has one of the highest malignancy rates in the world. The incidence of malignant melanoma in Colorado is increasing rapidly.
Causative factors in malignant melanoma include not only the cumulative effects of the sun over a period of time, but also to a greater degree, intermittent, painful, blistering sunburns that occur in childhood or early adolescence. A recent Harvard Medical School study suggests that even a single serious blistering sunburn in adolescence or childhood can double the risk of skin cancer later on, regardless of the total cumulative sun exposure or skin type. It is theorized that a serious burn may alter the genetic material in the pigment cells of the skin of a growing child, leading to the formation of unstable moles, which have the potential to turn malignant. Other risk factors include a family history of malignant melanoma, dysplastic nevi, or large congenital nevi.
With dysplastic nevi, the risk of malignant melanoma is 10 percent. With both a family history of malignant melanoma and dysplastic nevi, the risk approaches 100 percent. There is some controversy in the medical literature regarding the incidence of malignant melanoma in large congenital nevi, but commonly the risk quoted is 5-20 percent. Again, the general risk of malignant melanoma for the population as a whole is approximately 1.5 percent, i.e.: 1:150 in Caucasian Americans.
Earlier detection results in higher cure rates. A recent study at New York University Medical Center suggests a 10 a year survival for malignant melanoma less than .76 mm. thick is 99 percent. In contrast, the 10 year survival for a malignant melanoma greater than 3 mm. in thickness drops to 48 percent. The implication here is that early diagnosis of melanoma is critical to achieving a cure.
Early signs of malignant melanoma are a change in a pre-existing mole, or development of a new mole. Change in an existing mole is considered a 'medical emergency' by many clinicians. Non-malignant moles can certainly grow and change and not be malignant. Many times these require only careful follow up and possible serial photographs to document their change or stability.
Early signs of malignant melanoma include changes in a pre-existing mole, or the appearance of a brown-black or multi-colored patch where previously one did not exist. These changes are described as the ABCD's of melanoma. 'A' (asymmetry): A line down the center of many malignant moles would not leave two matching halves as in the case of common moles. 'B' (border): Many malignant melanomas have uneven 'ragged' edges as opposed to the smooth, even borders of non-malignant moles. 'C' (color): Often malignant melanomas have two or more colors ' usually black and brown, and sometimes blue and white. Non-malignant moles are generally one color. 'D' (diameter): Melanomas are usually larger than normal moles, which are 6 mm. or less in diameter (the size of a pencil eraser).
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SCARS/ WOUNDS/ HEALING SCAR REVISION
The effect of facial scarring is more than skin deep. Often it is very difficult to evaluate the emotional impact of such injuries. This is especially true with children who are unable to verbalize their feelings about the scars, or in males who are taught to minimize their concern about their appearance. It is apparent that many people undergo unnecessary deformity because either they or their families have failed to deal with their concern over the effects of facial scarring or have failed to seek advice on what can be done to improve the appearance of facial scars.
The treatment of facial scarring can be one of the most gratifying surgical procedures that a plastic surgeon does. On the other hand, it would be unfair if we did not point out that it is also one of the most difficult and challenging aspects of surgery. Unlike most cosmetic procedures, incisions usually cannot be hidden. The area of incision has already been predetermined by the injury. Often it is in the worst possible place, such as on the cheeks or on the jaw line.
TIMING SCAR REVISION
Patients tend to be impatient about the results of scar revision surgery. They are often already upset by the injury itself and find it difficult to understand that adequate and complete treatment may take many months or even several years.
Children and young adults are the most common victims of injury. Unfortunately, their skin tends to heal with more scarring. Although these scars tend to fade with time, it still makes the treatment program more difficult. Furthermore, it makes it much more important to wait before initiating treatment since a scar that looks poor a month or so after injury may continue to greatly improve in appearance for many months. Ultimately, it may be so unnoticeable as to not require treatment.
Although the repair carried out at the time of injury does influence the amount of scarring that exists after healing, even the most careful repair may not provide a totally acceptable result. When treating the initial injury, one is never sure how tissues will heal. Lost tissue may have to be replaced with grafts. Wounds may have to be closed under tension. These are only some of the factors that tend to promote increased scarring.
TYPES OF TREATMENT AVAILABLE FOR SCARS
Before instituting any form of treatment, we should watch the scar for a period of time. As long as there is significant improvement, then no surgical treatment should be instituted. Of course, proper treatment at the time of and following the injury will help to minimize scarring. Usually, within six-twelve months, the scar will have matured to near its optimum. If it is obviously unsatisfactory at that time, then scar revision should be considered.
Pressure and Massage: It is important to remember that sometimes conservative treatment is the best form of therapy. Repeated massage using vitamin E can greatly improve the appearance of scars. In some cases, special pressure dressing may also be of use.
Cortisone Drugs: Various types of cortisone drugs may be used either as injections, topical preparations, or in the form of special tapes. These may well improve the scar to a point where surgery is not required.
Re-excision: In many cases, simple excision and re-closure of the wound will greatly improve the result. We may be able to close the wound without the tension that was present at the time of the initial repair. Furthermore, what was originally a jagged cut may now be changed into a clean surgical incision.
Zig-Zag-Plasty: The Zig-Zag-Plasty is a technique of excising a scar and replacing the line with a geometric broken line. This type of wound tends to heal with less tension, and replaces a straight-line scar with a broken line scar that tends to be less apparent to the eye. This is one of the most common and successful techniques of dealing with facial scars.
Dermabrasion or Laser Resurfacing: Dermabrasion is a surgical planing technique that can be used to smooth down raised or uneven scars. Most commonly used for acne scarring, it is frequently helpful in the treatment of other injury scars.
Collagen Implantation: Collagen implantation involves the injection of a collagen material into the scar. It can be helpful in the treatment of depressed scars. In some cases, it can flatten the scars and make them almost imperceptible. Collagen does not result in permanent correction and treatment must be repeated after several months.
Silicone Pressure Therapy: In many cases, a silicone dressing can be applied to a raised scar and helps to soften or thin out the scar. The mechanism of this effect is unknown at the present time, but it has proven useful in many cases. It is very safe and simple to use. The special silicone sheet is cut to size and applied to the scar. It should be kept in place for 12 to 24 hours a day, depending on tolerance. Effects are not immediate, but results are usually seen within several weeks to months.
Serial Excision: In many cases, wide or extensive scarring cannot be adequately treated with one operation. A planned, staged approach may be required in which several operations are utilized to lead to the best possible result. In some situations, a device called a tissue expander can be used to hasten this type of reconstruction.
RISKS of SCAR REVISION
As mentioned, when dealing with scars, we must operate in the area predetermined by the accident. Most cosmetic procedures involve the placement of scars in inconspicuous areas or areas that are known to heal with minimal scarring. Any time an incision is made, a scar will result. Unfortunately, the thickness and the texture of the scar is only partially related to the skill of the surgeon and the procedure itself. In no case will scar revision surgery eliminate a scar completely. In nearly all cases, it will minimize the scar. In very rare cases, the scar could be made worse. Although very uncommon, it is a risk that must be accepted by the patient.
Postoperative healing requires some mandatory down time as part of the surgical recovery process. Post surgical healing requires the body to repair the surgical wound (whether in the skin, fat, muscle or bone) with scar tissue. The bruise and tissue fluid in the wound are gradually replaced by stronger scar or fibrous tissue over a period of 6-8 weeks. Until the time that the healing area is strong enough to maintain tissue integrity, the wound is held together by the sutures (stitches) placed at the time of surgery. Too much wound tension (stress) before the strength of the healing tissue is satisfactory, can cause disruption of the incision. I place sutures very precisely to account for these healing characteristics to maximize your postoperative activity, comfort, and safety. However, your inherent healing characteristics significantly dictate these parameters. Stretching, movement, massage, and return to normal activities of daily living in the early postoperative recovery allow for the optimal return to your full normal life style.
After the initial burst of high energy healing and the 'bulking up' of scar tissue, the wound enters a maturation phase, and the scar tissue becomes thinner, less red, and stronger. The maturing and stabilization of scar tissue occurs over a period of 6-12 months. Long-term changes tend to be more subtle, slower, and less evident than short-term changes that occur in the first 6-8 weeks.
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