John R. Tkach, M.D.
300 North Willson, Suite 203B
Bozeman, MT 59715
(406) 587-5442

Actinic Keratoses

Patient Information Sheet

The term actinic keratoses is a fancy Greek phrase that means that the sun has damaged the skin causing scaly areas to form. They are red, brown, or white scaly plaques caused by exposure to invisible ultraviolet light. Most are flat, but some get thick and scaly. Some get so scaly they form horn-like mounds of dead skin. Actinic keratoses are precancerous. They are not skin cancer yet, but they are on way to turning into skin cancer.

I treat hundreds of actinic keratoses daily in order to get rid of them before they do turn into skin cancer such as squamous cell cancer and basal cell cancer. What is the risk of any single actinic keratosis turning into cancer? I did a literature search on this. Dr. Kopf in New York City thinks it is 17%. An extensive study by the Dr.'s Graham in North Carolina puts it as 25%. The official number from the Skin Cancer Foundation is 10%.

My experience has been different. In my Montana patients, I think the lifetime risk of an untreated actinic keratosis turning into cancer is about 4%. I am very aggressive about treating all the actinic keratoses I can find on patients with this problem. Another way of looking at it is that even if you never see a doctor about an average actinic keratosis, the probability of its not turning into cancer is 96%. But consider this. Suppose we treat and cure 200 actinic keratoses on you over a few years with simple liquid nitrogen freezing. That will have saved you from having 8 cancers cut out. Think about that. Freezing is much cheaper and easier than cutting.

Actinic keratoses are a problem but not a crisis. You do not need to be frightened by them or distraught over them. However, you should be motivated enough to come in to see me for treatment early in the game. Freezing actinic keratoses is preventive medicine.

The ultraviolet light from the sun is invisible. You cannot see it or feel it. The damage it causes is insidious (hidden). Ultraviolet sunlight exposure causes damage to the chromosomes of the growing cells in the lower (basal cell) layer of the epidermis of the skin. This is the layer your skin grows from.

Every time you are in the sun, you get a little damage. This damage accumulates, and after some years scaly red spots appear. Under the microscope, the sun-damaged cells are red staining and 3 or 4 times larger than normal cells. These cells divide more rapidly than normal cells. Your body may recognize these sun-damaged cells as abnormal and try to destroy them with inflammation. Thus actinic keratoses may seem to flare up a few weeks or months and then get better for a while. But usually your body cannot get rid of them on its own. It needs some help.


Freezing actinic keratoses with liquid nitrogen is important. But, really, the single best thing you can do is to use a sunscreen. One of my favorite sunscreens is Neutrogena Dry Touch SPF 100.

Treatment Options

Actinic keratoses have about a 10% probability of turning into skin cancer if left untreated. The problem for me is that I cannot tell you which ones will turn into skin cancer and which ones won't. Therefore, it is necessary to treat them all. Fortunately the treatment I shall recommend is simple and not too expensive. Here are your treatment options:

  1. Do nothing- this is a mistake. Actinic keratoses, in my opinion, should be treated.
  2. Freeze with liquid nitrogen- This is what I recommend most of the time. It hurts a lot for about 1-2 seconds, but it usually works very well. It usually does not leave a scar, and it is not very costly. Rarely it is necessary to repeat liquid nitrogen treatment to an actinic keratosis if it does not clear up in 2 months. If an actinic keratosis does not clear up after 2 or 3 treatments, it may have already turned into skin cancer and require surgery. Let me know if it does not clear up. This is why I map out every treated keratosis in detail in my chart notes.
    Frozen areas usually heal leaving the color of the skin the same. Sometimes irritation from the treatment causes the area to darken for 2-4 months. If the treatment required was sever, it may leave a flat white area.
  3. Apply topical 5-fluorouracil cream (5 FU, Carac, Effudex)- This is an excellent treatment, and we may need to use it for you at some time. It has the advantage over liquid nitrogen that it kills hidden precancerous cells that I cannot see during my exam. It requires office visits every 1-2 weeks for 3-6 weeks. If liquid nitrogen seems adequate, I prefer to postpone 5FU therapy until it is really needed. 5-FU has a wide safety margin. For every good cell it kills, 5-FU kills 16 bad cells. It does make the skin very irritated.
    I guide people to use 5-FU 90 days based on my experience. 5-FU causes irritation and soreness during the course of treatment. But it is a very good treatment.
  4. Surgery- This is a good treatment. However, it is expensive and leaves scars. Most of the time, but not always, we can get rid of actinic keratoses without cutting. I am a little conservative about cutting. If I think liquid nitrogen or 5 FU will do the job, I would rather try them first. If the spot on you skin has already become a skin cancer, then it must be cut. But out a suspicious keratosis is never a wrong thing to do.
    About 12 time a year, I encounter actinic keratoses just won't go away with simple treatment. These I refer to a surgeon for surgery.
  5. Aldara (imiquimod)- is a cream that you rub into the sun-damaged areas once a day on Monday, Wednesday, and Friday. It stimulates your immune system to attack the bad cells. There are two problems. 20% of people have a genetic variation such as a Toll 7 receptor deficiency. As a result, Aldara does not work for them. I am one of those. It costs 4 times more than gold. But a $200 supply can go a long way.
  6. Peeling agents- Chemical face peels, mini dermabrasion, and superficial laser will temporarily seem to make keratoses go away. But they grow back in a few weeks to months. The reason for this is that the precancerous cells come from a reservoir in the basal layer. Peeling agents do not get that deep. If they do, they cause unacceptable scars. Liquid nitrogen tends not to damage the basement membrane.

The information provided in these patient information sheets is offered for general informational and educational purposes only; it is not offered as and does not constitute medical advice. In no way are any of the materials presented meant to be a substitute for professional medical care or attention by a qualified practitioner, nor should they be construed as such.

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