What is an Actinic Keratosis?
An actinic keratosis (AK), also known as a solar keratosis, is a
precancerous lesion of the outer layer of the skin (epidermis) that is
caused by long-term exposure to sunlight. AK’s are most commonly
found on sun-exposed areas of the face, ears, lips, chest, back, arms and
hands. Patients with fair skin and light-colored eyes and hair are at
greatest risk for developing AK’s. Individuals who are chronically
Immunosuppressed by organ transplantation, chemotherapy, or chronic
immune-deficiency disorders, are at heightened risk for developing AK’s.
What causes an Actinic Keratosis?
AK’s are caused by chronic exposure to ultraviolet radiation, typically from
sunlight. Frequent, long-term tanning bed use can also cause these
lesions. Ultraviolet radiation damages the DNA of the keratinocytes
(the cells that make up most of the epidermis), altering their normal life
cycle. This results in the development of scaly, rough, discolored,
painful lesions on the skin. The body’s DNA repair mechanism weakens
as patients age, resulting in damaged keratinocytes that escape the immune
system’s normal surveillance. AK’s are not life threatening, but if
left untreated, have the potential to progress into a squamous cell
carcinoma. Squamous cell carcinomas are serious cancers that possess a
small potential to metastasis. It is estimated that, if left
untreated, approximately 10% of actinic keratoses will develop into a
squamous cell carcinoma.
Treatment
The mainstay of treatment for actinic keratoses is proper sun protection and
avoiding excessive sun-exposure. Avoiding outdoor activities between
the hours of 11:00 am and 4:00 pm help to prevent development of AK’s.
Patients at high risk should make it a daily practice to wear a broad
spectrum sunscreen, rated at least SPF-30, on exposed areas of the
skin. Sunscreens should be reapplied every two hours during outdoor
activities. We recommend purchasing a sunscreen with either Titanium
Dioxide or Zinc oxide. Frequent use of sun-protective hats, shades,
eyeglasses and clothing also minimize AK development. There are myriad
of treatment options including cryotherapy (freezing lesion with liquid
nitrogen), curettage, topical chemotherapy (Efudex, Carac, etc…),
topical immune modulating therapy, Photodynamic Therapy (PDT), chemical
peels and laser resurfacing. We look forward to sharing our expertise
and determining to best treatment option for you.