An
actinic keratosis is a scaly or crusty bump that forms on the skin
surface. They are also known as a solar keratosis. Dermatologists
call them "AK's" for short. They range in size from as
small as a pinhead to an inch across. They may be light or dark,
tan, pink, red, a combination of these, or the same color as
your skin. The scale or crust is horn-like, dry, and rough, and is
often recognized easier by touch rather than sight. Occasionally it
itches or produces a pricking or tender sensation, especially
after being in the sun. It may disappear only to reappear later.
Half of the keratosis will go away on their own if you avoid all
sun for a few years. You will often see several actinic keratoses
shoe up at the same time. A keratosis is most likely to appear on
the face, ears, bald scalp, neck, backs of hands and forearms, and
lips. It tends to lie flat against the skin of the head and neck
and be elevated on arms and hands.
Why is it dangerous? Actinic keratosis can be the first step in
the development of skin cancer, and, therefore, is a precursor of
cancer or a Precancer. It is estimated that up to 10 percent of
active lesions, which are redder and more tender than the rest
will take the next step and progress to squamous cell
carcinomas.
They are usually not life threatening, provided they are detected
and treated in the early stages. However, if this is not done,
they can bled, ulcerate, become infected, or grow large and invade
the surrounding tissues and, 3% of the time, will metastasize or
spread to the internal organs.
The most aggressive form of keratosis, actinic cheilitis,
appears on the lips and can evolve into squamous cell carcinoma.
When this happens, roughly one-fifth of these carcinomas
metastasizes. The presence of actinic keratoses indicates that sun
damage has occurred and that any kind of skin cancer -- not just
squamous cell carcinoma can develop. People with actinic keratosis
are more likely to develop melanoma also. Sun exposure is the
cause of almost all actinic keratoses.
Sun damage to the skin accumulates over time. It is lifetime
sun exposure, not recent sun-tanning that adds to your risk.
Ultraviolet rays bounce off sand, snow, and other reflective
surfaces; about 80 percent can pass through clouds. The thinning
of the ozone layer may be allowing more ultraviolet rays reach the
earth. People who have fair skin, blonde or red hair, blue, green,
or gray eyes are at the greatest risk. Because their skin has less
protective pigment, they are the most susceptible to sunburn. Even
those who are darker-skinned can develop keratosis if they heavily
expose themselves to the sun without protection.
Individuals who are immunosuppressed as a result of cancer
chemotherapy, AIDS, or organ transplantation, are also at higher
risk. It seems that while your healthy, the body keeps them in
check. When you become ill they grow and become malignant more
often, although this is not yet proven. Because more than half of
an average person's lifetime sun exposure occurs before the age of
20, keratoses appear even in people in their early twenties who
have spent too much time in the sun.
How is it treated?
There are a number of effective treatments for eradicating
actinic keratoses. Not all keratoses need to be removed. The
decision on whether and how to treat is based on the nature of the
lesion, your age, and your health.
Curettage is a commonly used treatment. The physician scrapes
the lesion and takes a biopsy specimen to be tested for
malignancy. Bleeding is controlled by cautery --application of an
acid or heat produced by an electric needle. Shave Removal
utilizes a scalpel to shave the keratosis and obtain a specimen
for testing. The base of the lesion is destroyed, and the bleeding
is stopped by cauterization.
Cryosurgery freezes off lesions through application of liquid
nitrogen with a special spray device or cotton-tipped application.
It does not require anesthesia and produces no bleeding. The
longer the spot is frozen the better the chance it will never come
back. Longer freezes usually leave lasting white spots.
Dermabrasion removes the upper layers of the skin by sanding or
using a fine wire brush operating at 20-25,000 revolutions per
minute. The skin is left raw and crusted for a number of days.
Once healed after a few weeks, the skin is free from nearly all of
the warts, age spots, freckles, many wrinkles and keratosis. The
results are long lasting.
Chemical
peels: Chemical peels are a milder alternative that
has similar, but less complete, effects. Chemical Peeling makes
use of acids (jessners solution and/or trichloroacetic acid)
applied all over the area. The top layers of the skin peel off and
is usually replaced within seven days by growth of new skin.
Redness and soreness usually disappear after a few days.
Topical Medications: A prescription cream is effective in
removing keratoses, particularly when lesions are numerous. Some
health insurance plans now require this to be the first treatment
tried before they will pay for another approach. The patient twice
daily applies the medication, with progress checked by a
physician. 5-Fluorouracil (5-FU) cream is used for 2 to 4 weeks.
Treatment leaves the affected area temporarily reddened and raw
and will cause some discomfort resulting from skin breakdown.
Because many of the keratosis returns several years later, some
physicians are using less frequent applications for a longer time.
This avoids the Redness and soreness to a large degree, but the
keratoses come back sooner. Recent studies seem to show that the
more raw and inflamed the skin becomes, the better the end result.
Laser Surgery focuses the beam from a carbon dioxide or erbium-yag
laser onto the lesion. This treatment is being used more often now
these lasers are available, and appears equally effective. This
approach, like dermabrasion and chemical peeling, will not be
covered (or only partly covered) by insurance.
In conclusion, large, multiple or inflamed actinic keratosis
need to be treated to prevent their conversion to squamous cell
carcinoma. This avoid the potentially more invasive and extensive
treatment of a subsequent malignancy. Regular follow-up visits are
usually needed when there are many keratoses.