Atinic or Solar keratoses

Rough scaly spots on sun-damaged skin are called solar keratoses. They are also known as actinic keratoses. They should be distinguished from other kinds of keratosis (scaly spot) such as seborrhoeic keratosis, porokeratosis and keratosis pilaris.
What are solar keratoses?

Solar keratoses are a reflection of abnormal skin cell development due to exposure to ultraviolet radiation. They are considered precancerous.

They appear as multiple flat or thickened, scaly or warty, skin coloured or reddened lesions. A keratosis may develop into a cutaneous horn.

They are very common on sites repeatedly exposed to the sun especially the backs of the hands and the face, most often affecting the nose, cheeks, upper lip, temples and forehead. On the lips they are often called actinic cheilitis. They are especially common in fair-skinned persons or those who have worked outdoors for long periods without skin protection. Sun-damaged skin is also dry, discoloured and wrinkled.

Are solar keratoses dangerous?

Solar keratoses themselves are harmless, but they can be uncomfortable and unsightly.

The main concern is that solar keratoses can give rise to a type of skin cancer called squamous cell carcinoma. The risk of squamous cell carcinoma occuring in a patient with more than ten solar keratoses is about 10 to 15%.

Solar keratoses are usually removed because they are unsightly or uncomfortable, or because of the risk that skin cancer may develop in them. If a solar keratosis becomes thickened or ulcerated get it checked; it may have become a skin cancer. Squamous cell cancers often look like volcanoes erupting within the skin.

Treatment

Treatment of a solar keratosis requires removal of the defective skin cells. New skin then forms from deeper cells which have escaped sun damage.

It is not practical to remove all keratoses in those with very extensive sun damage; in such cases it is important to get rid of thickened or tender lesions as these are the ones at greatest risk of progressing to skin cancer.

Treatments may include:
· Cryotherapy
Freezing with CryoProbe causes blistering and shedding of the sun damaged skin. Keratoses treated on the face peel off after about 10 days, those on the hands in about 3 weeks, but those on the legs can take as long as twelve weeks to heal. A light freeze usually leaves no scar, but longer freeze times (necessary for thicker lesions or early skin cancers) result in a pale mark or scar. The lesions may recur in time, in which case they may be retreated by the same or a different method.
· Curettage & cautery

Curettage & cautery may be preferred with thicker keratoses, and is a common method of removing early squamous cell cancers. A specimen is sent for pathological examination. Curettage is the removal of a lesion by scraping it with a sharp instrument. Cautery or vascutouch burns the keratoses off and prevents bleeding. A scab forms which heals over a few weeks, leaving a small scar.

· Excision
Cutting the lesion out (excision biopsy) makes sure the lesion has been completely removed, confirmed by pathological examination. This is sometimes important if a lesion may be cancerous. Usually the surgical wound is sutured (stitched). The sutures are removed after a few days, the time depending on the size and location of the lesion. The procedure leaves a permanent scar.

· 5-Fluorouracil cream
5-Fluorouracil cream (5-FU, Efudix) is most useful when there are many keratoses on the face. The cream is applied onto facial skin once or twice daily for two to four weeks. The treated areas become red, raw and uncomfortable. Healing starts when the cream is discontinued, and the eventual result is usually excellent.
· Imiquimod

Imiquimod is an immune response modifier in a cream base. It is applied to areas affected by solar keratoses two or three times weekly for four to sixteen weeks. It causes an inflammatory reaction, which is maximal at about three weeks and then gradually settles down with continued use. The results are variable, but generally excellent.

· Photodynamic therapy
Photodynamic therapy (PDT) involves applying a photosensitizer (a porphyrin chemical) to the affected area prior to exposing it to a strong source of visible light. The treated area develops a burn and then heals over a couple of weeks or so.

Schedule an appointment to discuss with us your treatment options. The procedures have various advantages and disadvantages, including side effects, risk of scarring, and the number of treatment sessions required. Actinic keratosis is usually very responsive to treatment. Afterward you'll likely have regular follow-up visits to check for new patches or lesions.

Prevention

Prevention of actinic keratosis is important. The condition can be precancerous or an early form of skin cancer. Sun safety is necessary to help prevent development and recurrence of patches and lesions caused by actinic keratosis.

Take these steps to protect your skin from the sun:
· Limit your time in the sun. Avoid staying in the sun so long that you get a sunburn or a suntan. Both result in skin damage that can increase your risk of developing actinic keratosis and skin cancer. Sun exposure accumulated over time also may cause actinic keratosis. In addition to minimizing your time in the sun, set time limits when at the pool or beach or when you're spending time outdoors in the winter. Snow, water and ice all reflect and intensify the sun's harmful rays, and ultraviolet rays are strongest between 10 a.m. and 4 p.m. Clouds block only a small portion of UV rays.

Use sunscreen. Before spending time outdoors, apply a broad-spectrum sunscreen with a sun protection factor (SPF) of at least 30. Some sunscreens contain substances that block ultraviolet A (UVA) as well as ultraviolet B (UVB) rays. UVA rays penetrate into the deeper layers of your skin and can weaken your skin's immune system; UVB rays cause sunburn and play a significant role in superficial skin cancers. To identify UVA-blocking creams, look on the ingredient labels for avobenzone, titanium, dioxide, and transparent or microdispersed zinc oxide. Use sunscreen on all exposed skin, including your lips. Apply sunscreen 30 minutes before sun exposure, and reapply it every few hours or more often if you swim or sweat. Apply sunscreen to infants or young children before going outdoors and teach older children and teens how to use sunscreen to protect themselves. Keep a bottle of sunscreen in your car, your boat, with your gardening tools, and with your sports and camping gear to remind yourself and your family to use it.

· Cover up. For extra protection from the sun, wear tightly woven clothing that covers your arms and legs and a broad-brimmed hat, which provides more protection than does a baseball cap or golf visor. You might also consider wearing clothing or outdoor gear specially designed to provide sun protection.

· Avoid tanning beds and tan-accelerating agents. Tanning beds emit UVA rays, which are often touted as less dangerous than UVB rays. But UVA light penetrates deeper into your skin, causes actinic keratosis and increases your risk of skin cancer. As for suntan-accelerating products, the Food and Drug Administration warns against their use. Bronzing lotions that produce a tanned look without any sun exposure are a safe choice.

· Be aware of sun-sensitizing medications. Some common prescription and over-the-counter drugs can make your skin more sensitive to sunlight. These include antibiotics; certain cholesterol, high blood pressure and diabetes medications; birth control pills; non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin, others); and the acne medicine isotretinoin (Accutane). Ask your doctor or pharmacist about the side effects of any medications you take. If they increase your sensitivity to sunlight, be sure to take extra precautions.

· Check your skin regularly and report changes. Examine your skin regularly, looking for the development of new skin growths or changes in existing moles, freckles, bumps and birthmarks. With the help of mirrors, check your face, neck, ears and scalp. Examine the tops and undersides of your arms and hands.

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