Actinic Keratosis
What is it?
Actinic keratosis is a skin growth that is scaly
and irregular in shape. This type of growth is an
early sign of skin cancer, often leading to squamous
cell carcinoma. Referred to as actinic keratoses (AKs)
when there is more than one. Also known as sun spots,
senile keratoses, solar keratoses, and senile warts.
Who gets it?
People who expose their skin to the sun frequently,
especially without wearing sunscreen, are more likely
to develop actinic keratoses. They are also more
common in people with red hair and freckles. Although
AKs used to be more common in the elderly, they are
now seen more often in younger people due to changes
in our environment and lifestyles.
What causes it?
Actinic keratoses are caused by repeated and
prolonged exposure to the sun’s ultraviolet rays.
Ultraviolet B (UVB) radiation causes the cells on the
surface of the skin to undergo mutations that can
cause abnormalities in certain genes. One particular
gene that is affected is TP53, a gene that suppresses
tumors. When this gene is damaged, it allows
cancer-prone cells to divide, which creates the
growths known as actinic keratoses. They can
eventually develop into skin cancer.
What are the symptoms?
Actinic keratoses appear as small, scaly growths on
areas of the skin that have received sun exposure.
They are most common on the face, including the scalp
and ears, as well as on the backs of the hands. They
may first look like a flat, red spot, but become
thicker and scaly as they grow larger. They can also
be black or brown.
How is it diagnosed?
A specialist in skin conditions, called a
dermatologist, can recognize actinic keratoses during
a routine skin exam. AKs that are larger and very
thick need to be removed through a procedure called a
biopsy. The doctor will numb the area, then cut the
growth from the skin. The growth is then examined
under a microscope for abnormalities. Any skin growth
that undergoes a change in appearance, such as
bleeding or rapid growth, should be examined. It is
important to diagnose actinic keratoses in the early
stages, before they can become cancerous.
What is the treatment?
The treatment for actinic keratoses depends upon
the number and size of the lesions. If the growths are
small and show no signs of malignancy (cancer), they
can be frozen with liquid nitrogen, called cryotherapy.
Your doctor will want to recheck the growth areas at a
later time to ensure the skin is clear. Patients with
many AKs may be treated with photodynamic therapy.
With this method, the doctor applies a chemical called
aminolevulinic acid (ALA) to the skin. After it is
absorbed, the doctor shines a special blue light onto
the skin, which acts on the ALA solution in a way that
destroys any cancerous cells. Over a short period of
time, the AKs become crusty, and then heal. AKs may
also be treated with a chemotherapy cream called
5-fluorouracil. When the lesions become red and
crusty, application of the cream is stopped so the
lesions can heal. Other promising treatments focus on
stopping the gene mutations that cause AKs or altering
the skin’s immune system so it rejects the
pre-cancerous cells.
Self-care tips
You can prevent actinic keratosis by avoiding sun
exposure during the peak hours of 10 a.m. to 2 p.m. If
you do spend time in the sun, wear sunscreen with a
SPF of at least 15, a hat, and light, protective
clothing.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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