None — Actinic Keratoses
Actinic keratoses (AKs, also known as solar keratoses) are skin lesions that form from skin cells called keratinocytes. The lesions may appear as small scaly spots on the skin. Often the patches can't be seen, but can be felt due to their rough texture. Sometimes the patches are pink-red, brown, gray or yellowish black. Patches of AKs can be mistaken for a rash. Occasionally, an AK may take on a formation that resembles a miniature animal horn. AK lesions are most likely to develop in areas of the body that get the most exposure to the sun, like the face, lower lip, ears, scalp, neck, back of the hands and forearms.
The Skin Cancer Foundation estimates more than 10 million Americans have one or more AKs. They are one of the most common conditions seen by dermatologists. People at highest risk are those who have had significant unprotected sun exposure, those with fair skin or light-colored hair and eyes and persons with immune suppressing diseases (or patients taking immune suppressing drugs). Since AKs take time to develop, they are more commonly seen in middle- to late adulthood.
Treating AKs
Some people will seek medical advice for AKs because the lesions are unsightly or bothersome. However, the real concern is that some AKs can evolve into a form of skin cancer called squamous cell carcinoma (SCC). The American Osteopathic College of Dermatology estimates about 10 to 15 percent of AKs develop into SCC. However, there is no way for physicians to predict which lesions will become cancerous. Therefore, health experts often recommend all AK lesions be treated.
The most common therapies for AKs use some kind of destructive method to physically remove the lesion. Examples of destructive treatment include cryotherapy (use of very cold temperatures to freeze and destroy the abnormal cells), shaving or curettage (cutting them out). These techniques are best for people with a small number of individual lesions.
There are also several topical treatments for AKs. One of the first topical therapies was 5-fluorouracil (5-FU), a drug also used to treat other types of cancer. It works by targeting rapidly growing cells and stopping their growth. Two other topical medications are diclofenac (a nonsteroidal anti-inflammatory gel) and imiquimod cream.
Photodynamic Therapy for AKs
Photodynamic therapy (PDT) is a treatment that uses light-sensitive drugs (medications that become activated when exposed to certain kinds of light). One of the newest PDT therapies for AKs is METVIXIA™ (methyl aminolevulinate) cream. It is used in combination with a red light source, called Aktilite®, or any dose-regulated light source.
To use the treatment, the METVIXIA cream is first applied to the target area. Maria Tsoukas, M.D., Ph.D., Dermatologist with the University of Chicago Medical Center in Chicago, IL, says it takes about three hours for the active ingredient to reach inside the AK cells. So the area is covered with an occlusive dressing for a few hours. When the light therapy is ready to be given, the dressing is removed and the area is thoroughly cleaned. Then the light is directed at the area for 20 to 30 minutes. The drug manufacturer recommends two treatment sessions given one week apart.
During the treatment, patients may experience some burning, stinging or pain. Doctors may use different methods to control these symptoms, like a cooling fan or cooling compresses. After the treatment, the target area may appear red. Within two days, the skin begins to crust, peel and scab. Ice packs can limit inflammation and pain and topical steroids reduce itching.
One important part of the treatment process is that patients must avoid sun exposure from the time the cream is applied to 48 hours after the treatment. That's because the topical cream also makes the skin sensitive to sunlight, so patients can get a bad sunburn if they go out in the sun without any sun protection.
Tsoukas cautions that AKs tend to recur. So patients who have been treated for the condition should have regular follow-up skin examinations to screen and treat future AKs or early signs of other skin cancers.
For information on the treatment, click here.
For general information on actinic keratoses:
American Academy of Dermatology American Cancer Society American Osteopathic College of Dermatology The Skin Cancer Foundation