Actinic keratoses (AKs) are dry, scaly, rough-textured patches or lesions that form on the outermost layer of the skin after years of exposure to ultraviolet (UV) light, such as sunlight. These lesions typically range in color from skin-toned to reddish brown and in size from that of a pinhead to larger than a quarter. Occasionally, a lesion grows to resemble an animal horn and is called a “cutaneous horn.”
It is important that anyone with AKs be under a dermatologist’s care. AKs are considered the earliest stage in the development of skin cancer and have the potential to progress to squamous cell carcinoma, a type of skin cancer that can be fatal. Anyone who develops AKs has extensive sun-damaged skin. This makes one more susceptible to other forms of skin cancer, including melanoma. Melanoma is considered the most lethal form of skin cancer because it can rapidly spread to the lymph system and internal organs.
Causes of Actinic keratosis
Actinic Keratosis is seen especially in those who work outdoors, sailors, golfers, skiers and in those who have significant other recreational sun exposure.
The following are the two main causes of Actinic Keratosis:
Exposure To Carcinogenic Factors
A) Ultraviolet light – Most of this is from sunlight. Actinic keratoses are most commonly seen in fair skinned individuals who are unable to tan and is associated with an accumulated lifetime exposure to sun.
B) Ionizing radiation such as radiotherapy may also increase of skin cancers.
C) Chemicals such as arsenic increase the risk of skin cancers. Exposure is usually chronic and at low concentrations.
There are a number of rare genetic syndromes that increase the risk of skin cancer. For example, xeroderma pigmentosa results from a defect in DNA repair. This condition is associated with sun sensitivity, extensive freckling and the risk of all forms of skin cancers is up to 2,000 times that of the normal population.
Actinic keratosis Symptoms
The signs and symptoms of an actinic keratosis include:
- Rough, dry or scaly patch of skin, usually less than 1 inch (2.5 centimeters) in diameter
- Flat to slightly raised patch or bump on the top layer of skin
- Lesion that may develop a hard, wart-like surface
- Lesion that ranges in color from pink to red to brown, or flesh-colored
- Itching or burning in the affected area
Actinic keratoses are found primarily on areas exposed to the sun, including your face, lips, ears, back of your hands, forearms, scalp and neck. There may be a single lesion or several lesions.
An actinic keratosis sometimes resolves on its own, but typically returns again after additional sun exposure. If just scratched or picked off, an actinic keratosis will return.
Actinic keratosis Diagnosis
Doctors can easily diagnose actinic keratosis by examination. A biopsy may be required if the keratosis is large or thick to determine if it in fact is cancer.
Actinic keratosis Treatment
Actinic keratosis treatment options may include:
- Freezing (cryotherapy). An extremely cold substance, such as liquid nitrogen, is applied to skin lesions. The substance freezes the skin surface, causing blistering or peeling. As your skin heals, the lesions slough off, allowing new skin to appear. This is the most common treatment, takes only a few minutes, and can be performed in your doctor’s office.
- Creams or ointments. Some topical medications contain fluorouracil, a chemotherapy drug. The medication destroys actinic keratosis cells by blocking essential cellular functions within them. Another treatment option is imiquimod (Aldara), a topical cream that modifies the skin’s immune system to stimulate your body’s own rejection of precancerous cells.
- Chemical peeling. This involves applying one or more chemical solutions — trichloroacetic acid (TCA), for example — to the lesions. The chemicals cause your skin to blister and eventually peel, allowing new skin to form. This procedure may not be covered by insurance, because it’s considered cosmetic.
- Scraping (curettage). In this procedure, your surgeon uses a device called a curet to scrape off damaged cells. Scraping may be followed by electrosurgery, in which a pencil-shaped instrument is used to cut and destroy the affected tissue with an electric current.
- Photodynamic therapy. With this procedure, an agent that makes your damaged skin cells sensitive to light (photosensitizing agent) is either injected or applied topically. Your skin is then exposed to intense laser light to destroy the damaged skin cells.
- Laser therapy. A special laser is used to precisely remove the actinic keratoses and the affected skin underneath. Local anesthesia is often used to make the procedure more comfortable. Some pigment loss and scarring may result from laser therapy.
- Dermabrasion. In this procedure, the affected skin is removed using a rapidly moving brush. Local anesthetic is used to make the procedure more tolerable.
Talk to your doctor about your treatment options. The procedures have various advantages and disadvantages, including side effects, risk of scarring, and the number of treatment sessions required. Actinic keratoses are usually very responsive to treatment. Afterward you’ll likely have regular follow-up visits to check for new patches or lesions.