What is actinic keratosis?
An actinic keratosis (AK) or precancer, is a small, rough spot occurring on skin that has been chronically exposed to the sun. Actinic keratoses generally measure in size between 2 to 6 millimeters in diameter (between the size of a pencil point to that of an eraser). They are usually reddish in color and often have a white scale on top. In addition to feeling rough, actinic keratoses may feel sore or painful when fingers or clothing rub against them.
What causes actinic keratosis?
Actinic keratosis is caused by genetic damage to skin cells which usually result from sun exposure. Smoking may also contribute to their development as can suppression of the immune system. Sun damage to the skin accumulates over time so that even a brief exposure such as driving in a car can add to a lifetime total. If left untreated anywhere from 5-20% of actinic keratosis can develop into skin cancer of the squamous cell carcinoma type.
Can anyone get actinic keratosis?
Sun exposure is the cause of almost all actinic keratoses. Sun damage to the skin accumulates over time, so that even a brief exposure adds to the lifetime total. Certain groups of people are more at risk than others:
• People who have fair skin, blonde or red hair, and blue, green, or gray eyes are at the greatest risk, but darker-skinned people can develop keratoses if they expose themselves to the sun without protection.
• African-Americans rarely have these lesions.
• Individuals who are immunosuppressed as a result of cancer chemotherapy, AIDS, or organ transplantation, are also at higher risk.
One in six people will develop an actinic keratosis in the course of a lifetime, according to some estimates. Older people are more likely than younger ones to have actinic keratoses, because cumulative sun exposure increases with age.
What is the treatment for actinic keratosis?
The best treatment for an AK is prevention. For light-skinned individuals, especially, this means minimizing their sun exposure. By the time actinic keratoses develop, however, the relevant radiation is often so far in the past that prudent preventive measures play a relatively small role. Fortunately, treatment methods are usually simple and straightforward:
• Cryosurgery: Freezing AKs with liquid nitrogen often causes them to slough off and go away.
• Curettage: AK can be scraped off surgically with a specially designed instrument.
• Chemotherapy and immunotherapy topical creams contain the medications and cause AKs to become red and inflamed like a sun burn before they fall off. Although effective, this method often produces unsightly and possibly uncomfortable skin for a period of weeks.
• Photodynamic therapy involves the application of medication called aminolevulanic acid on the affected skin surface. We then expose this region to the wavelength of light that activates the chemical and causes a sunburn type reaction to the AKs. These areas become red and then slough off and heal typically within 7-14 days. We usually perform a series of two treatments approximately 8 weeks apart.
As with everything, each treatment has its advantages and disadvantages. Your practitioner will discuss these options with you and decide on the best treatment plan for your particular condition.