Actinic keratosis (or plural actinic keratoses), also called “solar keratosis “and “senile keratosis,” is a pre-malignant condition of thick, scaly, or crusty patches of skin; most commonly they are pink rough spots that feel like sandpaper. It is most common in fair-skinned people and it is associated with those who are frequently and chronically exposed to the sun, as it is usually accompanied by solar damage (e.g. farmers, construction workers, former lifeguards).
They are considered to be pre-cancerous, since some of them progress to squamous cell carcinoma, so treatment is recommended. Untreated lesions have up to 20% risk of progression to squamous cell carcinoma which can be a danger to your health.
Progressive development of these lesions occurs when skin is exposed to the sun constantly and thick, scaly, or crusty areas appear. The scaly or crusty portion is dry and rough. The lesions start out as flat scaly areas and later grow thicker and sometimes become sore.
An actinic keratosis commonly ranges between 2 and 6 millimetres in size, and is usually pink or red with a fine scale or roughness to it. The lesion may appear on any sun-exposed area, such as the face, ears, neck, scalp, chest, backs of hands, forearms, or lips.
Preventive measures recommended for actinic keratosis are similar to those for skin cancer:
- Not staying in the sun for long periods of time without protection (e.g., sunscreen, clothing, hats)
- Frequently applying quality sunscreens or sunblocks with SPF ratings greater than 30 and that also block both UVA and UVB light
- Wearing sun protective clothing such as hats, long-sleeved shirts, long skirts, or trousers
- Avoiding sun exposure during mid-day hours is very helpful because ultraviolet light is the most powerful at that time
Actinic keratoses are treated mainly because they are pre-cancerous, but also there is a cosmetic benefit to removing these lesions as many people find them unsightly and sometimes uncomfortable.
There are several treatments for the condition of actinic keratosis, but most commonly used are:
- Cryosurgery, e.g. with liquid nitrogen, by “freezing off” the actinic keratosis. This procedure is performed through your dermatologist at Toronto Dermatology Centre. This is particularly useful if you have just a few actinic keratoses.
- Creams, e.g. Imiquimod (Zyclara, Aldara) or Ingenol Mebutate (Picato) or 5-FU (Efudex), which are home therapies for treating larger areas of sun damage (areas of “field damage”). For people with many actinic keratoses or frequently recurring actinic keratoses, this therapy should be considered. These are prescribed by your dermatologist and can be a very useful adjunct to liquid nitrogen.
- Photodynamic therapy (PDT): this treatment involves applying a topical medicine, Levulan (ALA) or the newer version, Metvix (MLA). The medication is left to incubate on the affected area for an hour or so before an optical energy force is applied to activate the medicine. At Toronto Dermatology Centre we use the BBL (broadband light) that not only helps to clear the actinic keratosis lesions (and “subclinical lesions” or hidden lesions under the skin), but helps to alleviate brown spots (solar damage), decrease broken blood vessels and stimulate collagen production. Although there is minimal discomfort during the actual treatment, it is advised to avoid sunlight or bright indoor lighting for two days following your session. Generally at least two treatments are required, with the addition of maintenance treatments down the road as determined by your dermatologist.
- Repeat treatments or maintenance therapy in subsequent years is commonly required since “the damage was already done” many years prior which creates actinic keratoses. Your dermatologist will let you know if and when you need to repeat photodynamic therapy or home “field therapy” with creams.
Actinic keratosis is very common, affecting half of the global population. It is seen most often in fair-skinned individuals, and prevalence may vary with geographical location and age. People who take immunosuppressive drugs, such as organ transplant patients, are 250 times more likely to develop actinic keratoses (AKs) that may lead to skin cancer. If you feel that you may have AKs, it is important to get in to be assessed by your dermatologist as soon as possible. Early diagnosis and treatment is always the best course of action.
~ Sheri Roselle, Medical Esthetician at Toronto Dermatology Centre