|What is Actinic Keratosis (AK)?|
The most common type of precancerous skin lesion, AKs appear on skin that has been frequently exposed to the sun or to artificial sources of UV light, such as tanning machines. In rare instances, extensive exposure to X-rays can cause them. Above all, they appear on sun-exposed areas such as the face, bald scalp, ears, shoulders, neck and the back of the hands and forearms. They can also appear on the shins and other parts of the legs. They are often elevated, rough in texture and resemble warts. Most become red, but some are light or dark tan, white, pink and/or flesh-toned. They can also be a combination of these colors.
|Actinic Keratosis (AK)?|
In the beginning, AKs are frequently so small that they are recognized by touch rather than sight. They feel as if you were running a finger over sandpaper. Patients may have many times more invisible (subclinical) lesions than those appearing on the surface.
Most often, actinic keratoses develop slowly and reach a size from an eighth to a quarter of an inch. Early on, they may disappear only to reappear later. Occasionally they itch or produce a pricking or tender sensation. They can also become inflamed and surrounded by redness. In rare instances, AKs can even bleed.
How to spot an Actinic keratoses
Actinic keratoses typically occur on the face, lips, ears, bald scalp, shoulders, neck and back of the hands and forearms. Ranging in size from a tiny spot to as much as an inch in diameter, AKs usually appear as small crusty or scaly bumps or “horns.” The base can be dark or light skin-colored and may have additional colors such as tan, pink and red. Symptoms of actinic cheilitis, a variant of AK that appears on the lower lip, may include chapping, cracks and whitish discoloration.
Examples of typical actinic keratoses are shown here, so examine your skin regularly for lesions that look like them. But it’s not always that simple: Many actinic keratoses have quite a different appearance, so if you find any unusual or changing growth, be suspicious and see your doctor promptly.
Treatments for Actinic keratoses
Early treatment can eliminate almost all actinic keratoses before they become skin cancers. If an AK is suspected to be an early cancer, the physician may take tissue for biopsy by shaving off a portion of the AK with a scalpel or scraping the lesion with a curette (an instrument with a sharp ring-shaped tip). The curette may also be used to scrape off the base of the lesion. Bleeding is stopped with an electrocautery needle, or by applying trichloroacetic acid (TCA). Local anesthesia is necessary.
Depending on the nature of the growth and the patient’s age and health, various treatment options are available for actinic keratosis, including the following :
These are most widely used for individual AKs.
- Cryosurgery: The physician applies liquid nitrogen to the AK to freeze the tissue. Later, the lesion and surrounding frozen skin may blister or become crusted and fall off.
- Curettage and desiccation: The physician scrapes or shaves off part or all of the lesion, then applies heat or a chemical agent to stop the bleeding and potentially kill any remaining AK cells.
- Laser surgery: The physician uses intense light to vaporize AK tissue.
If you have numerous or widespread actinic keratoses, your doctor may prescribe a topical cream, gel or solution. These can treat visible and invisible lesions with a minimal risk of scarring. Doctors sometimes refer to this type of therapy as “field therapy,” since the topical treatments can cover a wide field of skin as opposed to targeting isolated lesions.
Photodynamic therapy (PDT)
Photodynamic therapy (PDT) is especially useful for widespread lesions on the face and scalp. The physician applies a light-sensitizing topical agent to the lesions, then uses a strong light to activate the topical agent, destroying the AKs while sparing healthy tissue.
Doctors may combine therapies for a period of time to treat AKs. Typically, treatment regimens combine cryosurgery with PDT or a topical agent like imiquimod, diclofenac, ingenol mebutate, or 5-fluorouracil (5-FU). The topical medications and PDT may also be used alternately every three months, six months or year, as determined by the physician at follow-up skin examinations.
Reference : http://www.skincancer.org/