Actinic Keratosis

Overview, Causes, & Risk Factors

Actinic keratosis is a common premalignant skin lesion seen on areas of thebody that have been exposed to sun. Premalignant means that the lesions havethe potential to become skin cancer.

What is going on in the body?

Sun damage over many years causes changes in the skin. When the cells start togrow in an irregular and unusual fashion, actinic keratosis may develop. Thelesions are not true deep or invasive skin cancers, but the area of skin is nolonger normal.

What are the causes and risks of the condition?

Actinic keratosis is caused by long-term exposure to the sun. The number oflesions increases with age. A person with light skin has a higherrisk of developing actinic keratosis. Someone who works outdoors, such as alifeguard or construction worker, is at greater risk. Certain antibiotics, suchas tetracycline, increase a person’s risk.

People withaltered immune systems are also at increased risk for actinic keratosis. Thisgroup includes:

  • people with HIV orother acquired immunodeficiencydisorders
  • children born with immunodeficiency disorders
  • individuals who are taking powerful immunosuppressive medicines after organtransplants
  • persons who are taking chemotherapy for treatment of cancer or other disorders
  • Symptoms & Signs

    What are the signs and symptoms of the condition?

    The skin lesions of actinic keratosis start out as flat, scaly,red patches. These patches are seen on areas of the skin that are exposed tothe sun. They are dry, horny, and rough. The lesions are often felt more easilythan they are seen. Sometimes the lesions may be tender or causeitching.

    The lesions grow slowly and range from 1/8 to 1/4 inch in diameter.They may go away and return at a later time. Over time, the lesions may changeto wartlike white, hard crusts. Common locations for the lesions include:

  • backs of hands and forearms
  • bald scalp
  • face and ears
  • lips
  • neck
  • Diagnosis & Tests

    How is the condition diagnosed?

    Diagnosis of actinic keratosis begins with a medical history andphysical exam. A biopsy may be performed to confirm the diagnosis. This involvestaking a sample of the skin from the affected area and examining it under amicroscope.

    Prevention & Expectations

    What can be done to prevent the condition?

    Actinic keratosis can be prevented by using skin cancer preventiontechniques. A person should limit time in the sun, especially during the middleof the day. Regular use of sunscreen outdoors helps prevent actinic keratosis.Protective clothing, such as a hat and long sleeves, will also help. Tanningparlors and artificial tanning machines should be avoided.

    What are the long-term effects of the condition?

    Between 10% and 20% of actinic keratosis lesions will becomeskincancer over time. The lesions may also be painful or cosmeticallyembarrassing.

    What are the risks to others?

    Actinic keratosis is not contagious and poses no risk toothers.

    Treatment & Monitoring

    What are the treatments for the condition?

    Treatments for actinic keratosis include:

  • chemical peeling, which uses trichloroacetic acid or phenol to cause thetop layer of skin to slough off
  • cryosurgery, which uses extreme cold to destroy abnormal cells
  • curettage and desiccation, which involves scraping of the lesion followedby electrocautery to control bleeding
  • dermabrasion, which involves sanding off the top layers of the lesion
  • laser surgery, whichremoves the lesions
  • shave removal with a scalpel, followed by electrocautery to stopbleeding
  • topical medicines, such as 5-fluorouracil or masoprocol, which remove thelesions
  • What are the side effects of the treatments?

    Medicines may cause loss of pigmentation in the treated skin areaor allergic reactions.Surgical procedures can cause bleeding, infection, or allergic reaction to anesthesia.

    What happens after treatment for the condition?

    After treatment, the sites usually heal into smooth skin and are unnoticeable.The person will still have a tendency to develop precancerous lesions. Theperson should follow skin cancer prevention guidelines for therest of his or her life.

    How is the condition monitored?

    A person with actinic keratosis is much more likely to have true skin cancerthan most people. He or she should have regular skin checks with the healthcareprovider. Any new or worsening symptoms should be reported to theprovider.

    Article type: xmedgeneral