What are keratoses?

Keratosis refers to a scaly growth on the skin.  There are two forms: actinic keratoses and seborrheic keratoses.  

What are Actinic Keratoses? 

Actinic Keratoses (AKs) are rough, scaly spots that occur on skin that has been exposed to the sun over a period of years.  These lesions are the result of DNA damage to the skin by the sun’s ultra violet radiation.  AKs are usually small – most are no bigger than a pencil eraser – but  some may be as big as a half-dollar in diameter.  They may be skin-toned, reddish brown, or yellowish in color.  They have scaly, irregular surfaces that are rough to the touch and sometimes a stinging sensation is noted.  The number of AKs ranges from one or a few to many.  People who have fair skin and light-colored hair and eyes are at the greatest risk of developing AKs. Individuals who are immunosuppressed, either by cancer chemotherapy or organ transplant medications, are also at high risk for development of AKs.  Seborrheic keratoses on the other hand are warty growths that occur on the face, scalp, trunk and extremities.  These are not usually felt to be due to excess ultraviolet exposure.

Are AKs cancerous? 

AKs are cancerous lesions, but they can usually be completely cured with liquid nitrogen applied by your dermatologist. Sometimes AKs will resolve without treatment, provided the skin is not further damaged by continued sun exposure.  However, if an AK persists for a month or more it should be removed. These lesions can progress to squamous cell carcinoma.  Health care providers usually recommend treatment for large AKs or areas of the skin with many lesions.

How are AKs treated? 

When there are just a few small AKs, freezing with liquid nitrogen (cryotherapy) is an option. Freezing causes blistering and shedding of the sun-damaged skin.  With this approach, you will experience a stinging and burning sensation at the treatment site which resolves quickly, usually beginning to subside shortlyafter application.  Healing occurs in about 2-4 weeks, depending on the size and location of the keratosis. Topical Vitamin C serum and Vitamin E lotion applied twice daily as soon as possible after the liquid nitrogen can speed resolution of the treated lesions.

These lesions can be removed surgically, often with the use of a scraping instrument.  Surgical removal is usually reserved for large lesions or for any AK that looks like it might be cancerous. The growth is sent to a laboratory for microscopic examination and analysis – a biopsy.   

Another commonly used treatment is a topical prescription medication called 5-fluorouracil (or 5-FU), which destroys sun-damaged skin cells.  This treatment is preferred by many health care providers especially when there are many AKs – particularly on the scalp, face, ears, neck or arms.  The medication is rubbed on the AKs for about two weeks.  After about a week, the treated area begins to get red and then becomes raw.  The applications are continued until your health care provider determines that you have the optimal results.  Healing starts when the 5-FU applications are stopped.  Healing can be hastened with topical hydrocortisone cream applied twice daily for about a week after the 5-FU is discontinued.  Topical Vitamin C and Vitamin E applied twice daily can also speed resolution of the treated lesions.

Laser resurfacing is another option for people with many lesions.  While this method is not covered by insurance, it can remove AKs, seborrheic Keratoses, age spots, eyelid laxity, and fine wrinkles all in one treatment with just a week of "down time".

Can I prevent more AKs from developing?

Sun protection is the best defense against the development of AKs.  You can protect yourself from excessive sun exposure by avoiding peak sun exposure (9 am to 4 pm) and wearing a hat and sun protective clothing to shield your skin from the sun.  Ultraviolet light in UV-A spectrum also causes skin cancer; however, most sunscreens only block UV-B rays.  For this reason, it's important to use clothing and avoid the sun when it's most intense.

In addition, the use of topical antioxidants, such as topical Vitamin C,  Vitamin E, and Retin A (prescription required) has shown efficacy in preventing AKs.

Is the treatment painful?

There will be pain or a stinging sensation lasting from 5 to 30 minutes following the actual freezing.  There may be some redness and swelling. Once this pain stops, you should have no further pain, but the area may itch or be tender for a day or two. Topical Vitamin C serum and Vitamin E lotion applied as soon as possible after the liquid nitrogen and twice daily can speed resolution of the treated lesions.

What can I expect after treatment?

By one to two days a blister may form in the treated area.  There may be some blood in the blister producing a purple color, especially on the hands in patients who take aspirin.  Do not be concerned about this. If the blister is large, sterilize a needle and prick the blister once to allow fluid to seep out onto a tissue.  Do not remove the blister roof; an infection may result if you do.

In some cases just a scab will form without a preceding blister.  Once the scab appears, the skin will gradually heal beneath it and eventually shed the scab. This will take between 14 and 28 days. When the scab comes off, the underlying skin will be temporarily slightly pink or red in color.

How should I care for blisters that occur?

Simply leave the blister or scab alone. You may wash and use cosmetics as usual.  If a blister does form that is painful, especially on the bottom of the foot, it is best to return to the physician's office to have it drained.  It’s better to leave the blister roof in place since this protects against infection.

If a blister breaks, cover it with a Band-Aid and change it daily until a dry crust forms over the area.

Signs of infection, such as redness, swelling, increased pain or pus should prompt a call to your physician.

If the growth has not disappeared completely by 4-6 weeks, you should be seen again by your physician.  In some cases, the area may require several treatments or even a biopsy to confirm the diagnosis and make sure the growth is not skin cancer.

How can I prevent the need for liquid nitrogen treatments?

If you received liquid nitrogen treatment for keratosis or skin cancer, you may consider a more proactive approach to prevention. Many people become resigned to the twice yearly visit to their dermatologist for liquid nitrogen treatment.  This doesn't have to be the case.  Your skin has DNA repair mechanisms that can bring your skin nearly back to normal within a year.  Vitamin D3, taken internally, is responsible for much of the DNA repair, so have your blood levels checked (they should be around 50 ng/ml) and maintain your Vitamin D level with supplements.  Also, use of a hat, sun protective clothing, avoidance of peak sun exposure and use of topical antioxidants like topical Vitamin C serum and Vitamin E lotion applied twice daily will help repair and prevent additional premature aging.