SKIN
ANATOMY, CANCER, SCARS
SKIN ANATOMY AND PHYSIOLOGY
When we speak of vital organs, we usually think of heart, lungs,
and brain. When any stops functioning, we cant survive. Another vital organ, often overlooked,
is our skin. We cant 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 dont
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 its dry,
it will crack. Despite the common advice to drink eight glasses of water a day,
an excessive intake of fluids doesnt 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 bodys 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.
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E. SKIN CANCER
- Causes of Skin Cancer
a. 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.
b. 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
a. 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.
b. Prices of Reconstruction.
Although reconstructive techniques are available in modern plastic surgery,
the procedures are expensive both monetarily, in time off work and emotionally
c. 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.
SKIN
CANCER
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 bodys
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.
Mohs 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
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 ABCDs 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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