Actinic Keratosis

An actinic keratosis, also known as a solar keratosis, is a scaly or crusty bump that arises on the skin surface. The base may be light or dark, tan, pink, red, or a combination of these ... or the same color as your skin. The scale or crust is dry and rough. Occasionally it itches or produces a pricking or tender sensation. An actinic keratosis can appear anywhere but is most likely to appear on sun exposed areas such as the face, ears, bald scalp, neck, backs of hands and forearms, and lips.

Why are actinic keratosis important?

Actinic Keratosis are considered pre-cancerous because they can be the first step in the development of a type of skin cancer, called squamous cell carcinoma. While all actinic keratosis have the potential to turn into squamous cell carcinoma, some are riskier than others. A dermatologist can diagnose the lesion and assess the risk.

What is the Cause?

Sun exposure is the cause of almost all actinic keratosis. Sun damage to the skin accumulates over time, so that even a brief exposure adds to the lifetime total. The likelihood of developing keratosis is highest in regions close to the equator. However, regardless of climate, everyone is exposed to the sun. Ultraviolet rays reflect off sand, snow, and other surfaces. About 80 percent of ultraviolet rays can pass through clouds.

Who is at Risk?

People who have fair skin, blonde or red hair, blue, green, or gray eyes are at the greatest risk. Because their skin has less protective pigment, they are the most susceptible to sunburn. Even those who are darker-skinned can develop keratosis if they expose themselves to the sun without protection. African-Americans, however, rarely have these lesions.

Individuals, who are immunosuppressed as a result of cancer, chemotherapy, AIDS, or organ transplantation, are also at higher risk.

How Common is It?

One in six people will develop an actinic keratosis in the course of a lifetime, according to the best estimates. Older people are more likely than younger ones to have actinic keratosis, because cumulative sun exposure increases with the years.

A survey of older Americans found keratosis in more than half of the men and more than a third of the women aged 65 to 74 who had a high degree of lifetime sun exposure. Some experts believe the majority of people who live to the age of 80 have keratosis. Because more than half of an average person's lifetime sun exposure occurs before the age of 20, keratosis appear even in people in their early twenties who have spent too much time in the sun with little or no protection.

How is It Prevented?

The best way to prevent actinic keratosis is to protect yourself from the sun.

    • Limit the amount of time spent in the sun.
    • Avoid the peak hours from 10 a. m. to 4 p.m.
    • Cover up with protective clothing, including a broad-brimmed hat.
    • Wear a broad-spectrum sunscreen with a sun protection factor (SPF) of 15 or greater.
    • Avoid tanning parlors and artificial tanning devices.
    • Keep newborns out of the sun. Sunscreens can be used on babies over the age of six months.
    • Teach your children good sun-protection practices.
    • Perform regular skin self-examination and consult a dermatologist if you find a suspicious area.
    • Actinic keratosis is skin cancer's warning signal. Heed that signal.

How is It Treated?

There are a number of effective treatments for actinic keratosis. The right treatment for you will depend on the size and site and aggressiveness of the lesion, as well as the health and wishes of the patient. Your dermatologist can help you choose among the following possible treatments:

Cryosurgery– This is the most commonly used procedure. It involves freezing off the lesions through application of liquid nitrogen with a special spray device or cotton-tipped applicator. It does not require anesthesia and produces no bleeding. There is a slight risk of scaring and hypopigmentation.

Topical Medications – Multiple topical medications can be used at home to treat these lesions, especially when the lesions are large or numerous. Those medications include fluorouracil, imiquimod, Picato, Soloraze.

Shave removal, Curettage and Electrodessication, or surgical removal

Photodynamic therapy

Actinic keratosis: Overview

Also called solar keratosis

An AK forms when the skin is badly damaged by ultraviolet (UV) rays from the sun or indoor tanning. Most people get more than one AK. When you have more than one AK, you have actinic keratoses, or AKs.

Anyone who has many AKs should be under a dermatologist’s care. Most people who have many AKs continue to get new AKs for life. AKs are considered precancerous. Left untreated, AKs may turn into a type of skin cancer called squamous cell carcinoma.

By seeing a dermatologist for checkups, the AKs can be treated before they become skin cancer. If skin cancer does develop, it can be caught early when treatment often cures skin cancer.

Photograph used with permission of the American Academy of Dermatology National Library of Dermatologic Teaching Slides.

References:
Duncan KO, Geisse JK, Leffell DJ. “Epidermal and Appendageal Tumors.” In: Wolff K, Goldsmith LA, Katz SI, et al. editors. Fitzpatrick’s Dermatology in General Medicine, 7th ed. United States of America, McGraw Hill Medical; 2008. p.1007-14.
Rigel DS, Cockerell CJ, Carucci J et al. “Actinic Keratosis, Basal Cell Carcinoma, and Squamous Cell Carcinoma.” In: Bolognia JL, Jorizzo JL, Rapini RP, et al. editors. Dermatology, 2nd ed. Spain, Mosby Elsevier; 2008. p. 1645-6.

Actinic keratosis: Signs and symptoms

Signs of actinic keratosis

The following photographs show signs of actinic keratoses (AKs).

If you see any of these signs on your own skin, you should see a dermatologist. Left untreated, AKs may turn into a type of skin cancer called squamous cell carcinoma. People who have AKs also have a higher risk of getting other types of skin cancer. When found early, most skin cancers can be cured.

Symptoms of actinic keratoses

Most people who get AKs do not have any symptoms. They only notice changes to their skin. Symptoms can occur. A few symptoms to watch for are:

  • Rough-feeling patch on skin that cannot be seen.
  • Rough patch or growth that feels painful when rubbed.
  • Itching or burning.
  • Lips feel constantly dry.

Actinic keratosis: Now you see it, now you don’t

An AK can come and go. An AK can appear on the skin, remain for months, and then flake off and disappear. The skin can suddenly feel smooth. Many AKs re-appear in a few days to a few weeks. They often re-appear when the person goes outdoors without sun protection.

Even if an AK does not re-appear, you should see your dermatologist. AKs form when the top layer of skin is badly damaged. You can get more AKs. If the damage grows deeper, skin cancer can develop.

Photographs 1, 2, 5, 7, and 9 used with permission of the American Academy of Dermatology National Library of Dermatologic Teaching Slides.

*Photograph used with permission of the Journal of the American Academy of Dermatology. J Am Acad Dermatol.1997;36:236-8.

**Photograph used with permission of the Journal of the American Academy of Dermatology. J Am Acad Dermatol.1998;39:S74-8.

*** Photographs used with permission of the Journal of the American Academy of Dermatology. J Am Acad Dermatol 2000;42:S8-10.

References:
Bhatia ND. “Medical Management of Actinic Keratoses.” Focus session presented at the 2011 American Academy of Dermatology Summer Academy Meeting: New York City. Aug 2011.
Moy RL. “Clinical presentation of actinic keratoses and squamous cell carcinoma.” J Am Acad Dermatol 2000 Jan; 42:S8-10.
Odom R. “Managing actinic keratoses with retinoids.” J Am Acad Dermatol 1998 Aug;39:S74-8.
Sander CA, Pfeiffer C, Kligman AM et al. “Chemotherapy for disseminated actinic keratoses with 5-fluorouracil and isotretinoin.” J Am Acad Dermatol 1997 Feb;36:236-8.

Actinic keratosis: Who gets and causes

People who are most likely to get AKs have one or more of the following traits:

  • Fair skin.
  • Hair color is naturally blond or red.
  • Eyes are naturally blue, green, or hazel.
  • Skin freckles or burns when in the sun.
  • 40 years of age or older.
  • Weak immune system, which has many causes including:
  • Have a medical condition that makes the skin very sensitive to UV rays, such as:
  • Work with substances that contain polycyclic aromatic hydrocarbons (PAHs), such as coal or tar. Roofers have a higher risk of getting AKs because they work with tar and spend their days outdoors.

AKs usually appear after age 40. People who live in places that get intense sunlight all year, such as Florida and Southern California, may get AKs earlier. AKs also often appear much earlier in people who use tanning beds and sun lamps.

What causes AKs?

Ultraviolet (UV) rays cause AKs. Most people get exposed to UV rays from being outside during the day or using tanning beds.

When UV rays hit our skin, the rays damage our skin. When we are young, the body can repair some of the damage. Over time, the damage accumulates, and the body is less able to repair itself. We eventually see UV-damaged skin. If UV rays continue to hit the skin, people get AKs.

References:
Bhatia ND. “Medical Management of Actinic Keratoses.” Focus session presented at the 2011 American Academy of Dermatology Summer Academy Meeting: New York City. Aug 2011.
Moy RL. “Clinical presentation of actinic keratoses and squamous cell carcinoma.” J Am Acad Dermatol 2000 Jan; 42: 8-10.
Odom R. “Managing actinic keratoses with retinoids.” J Am Acad Dermatol 1998 Aug; 39: S74-8.
Rigel DS, Cockerell CJ, Carucci J et al.“Actinic Keratosis, Basal Cell Carcinoma, and Squamous Cell Carcinoma.” In: Bolognia JL, Jorizzo JL, Rapini RP, et al. editors. Dermatology, 2nd ed. Spain, Mosby Elsevier; 2008. p. 1645-6.

Actinic keratosis: Diagnosis and treatment

How do dermatologists diagnose actinic keratosis?

Dermatologists diagnose an actinic keratosis (AK) by closely examining the skin.

If your dermatologist finds a growth that is thick or looks like skin cancer during the exam, your dermatologist will likely perform a skin biopsy. Your dermatologist can safely perform a skin biopsy during an office visit.

When found early and treated, skin cancer is often cured.

How do dermatologists treat AKs?

There are many treatments for AKs. Some treatments your dermatologist can perform in the office. Other treatments you will use at home. The goal of treatment is to destroy the AKs. Some patients receive more than one type of treatment. Treatments for AKs include:

In-office procedures:

  • Cryotherapy: Destroys visible AKs by freezing them. The treated skin often blisters and peels off within a few days to a few weeks. This is the most common treatment. When the skin heals, you may see a small white mark.
  • Chemical peel: This is a medical chemical peel. You cannot get this peel at a salon or from a kit sold for at-home use. This strong peel destroys the top layers of skin. The treated area will be inflamed and sore, but healthy new skin will replace it.
  • Curettage: Your dermatologist carefully removes a visible AK with an instrument called a curette. After curettage, your dermatologist may use electrosurgery to remove more damaged tissue. Electrosurgery cauterizes (burns) the skin. New healthier skin will appear.
  • Photodynamic therapy (PDT): A solution is applied to make the skin more sensitive to light. After a few hours, the treated skin is exposed to a visible light, such as blue or laser light. The light activates the solution and destroys AKs. As the skin heals, new healthy skin appears.
  • Laser resurfacing: Much like a chemical peel, a laser can remove the surface layer of the skin. This destroys AK cells. After treatment, the skin will be raw and sore. The skin heals within 1 or 2 weeks, revealing healthier new skin.

Prescription medicine:

Your dermatologist may prescribe a medicine that you can use at home to treat AKs. Medicines that dermatologists prescribe include:

  • 5-fluorouracil (5-FU) cream: This is chemotherapy that you apply to the skin. It causes temporary redness and crusting. Patients typically apply 5-FU twice daily for 2 to 4 weeks. A person who has lots of damaged skin may need to use 5-FU longer. 5-FU causes sun-damaged areas to become raw and irritated. As the skin heals, healthy skin appears. Another treatment such as cryotherapy may be necessary to treat thick AKs.
  • Diclofenac sodium gel: This is a non-greasy gel. You apply it to skin with lots of AKs. Patients apply the medicine twice a day for about 2 to 3 months. During this time, you must protect your skin from the sun. You will see the best results about 30 days after you stop applying the gel. Some AKs can remain. Your dermatologist will treat these, often with cryotherapy.
  • Imiquimod cream: This cream helps boost your body’s immune system so that your body can get rid of the diseased skin cells. You will apply this cream to your skin as directed by your dermatologist. Most patients apply imiquimod for several weeks. Imiquimod causes the skin to redden and swell. After you stop using the medicine, the skin heals.
  • Ingenol mebutate gel: This gel works in two ways. It boosts the body’s immune system. It also is a type of chemotherapy for the skin. One formula is used to treat AKs on the head and scalp and is applied for 3 days in a row. The other formula treats AKs on the legs, arms, and torso. Patients apply this formula for 2 days in a row. Both formulas can cause rapid redness and swelling. As the skin heals, the redness and swelling clear.

Researchers continue to look for new treatments for AKs. No one treatment works on all AKs.

Outcome

Some people get only a few AKs. These AKs often clear with treatment.

If you have many AKs, you need to be under a dermatologist’s care. AKs form in skin that has been badly damaged by the sun or indoor tanning. This damage often causes people to get new AKs for life. Left untreated, AKs may turn into squamous cell carcinoma, a type of skin cancer. With frequent checkups, this skin cancer can be found early and removed. When found early and treated, most skin cancers can be cured.

Your dermatologist will tell you how often you should return for checkups. Some patients need a checkup once every 8 to 12 weeks. Others return for a checkup 1 or 2 times per year.

You should keep every appointment. If skin cancer develops, the sooner it is detected and removed, the better the outcome.

References:
Bhatia ND. “Medical Management of Actinic Keratoses.” Focus session presented at the 2011 American Academy of Dermatology Summer Academy Meeting: New York City. Aug 2011.
Dinehart SM. “The treatment of actinic keratoses.” J Am Acad Dermatol 2000 Jan; 42: 25-8.
Feldman SR, Fleischer AB, Jr., Williford PM et al. “Destructive procedures are the standard of care for treatment of actinic keratoses.” J Am Acad Dermatol 1999 Jan; 40: 43-7.
Moy RL. “Clinical presentation of actinic keratoses and squamous cell carcinoma.” J Am Acad Dermatol 2000 Jan;42:S8-10.
Odom R. “Managing actinic keratoses with retinoids.” J Am Acad Dermatol 1998 Aug; 39: S74-8.
Rigel DS, Cockerell CJ, Carucci J et al.“Actinic Keratosis, Basal Cell Carcinoma, and Squamous Cell Carcinoma.” In: Bolognia JL, Jorizzo JL, Rapini RP, et al. editors. Dermatology, 2nd ed. Spain, Mosby Elsevier; 2008. p. 1645-6
Salasche SJ, Levine N, Morrison L. “Cycle therapy of actinic keratoses of the face and scalp with 5% topical imiquimod cream: An open-label trial.” J Am Acad Dermatol 2002 Oct; 47: 571-7.
Stockfleth E, Meyer T, Benninghoff B et al. “A randomized, double-blind, vehicle-controlled study to assess 5% imiquimod cream for the treatment of multiple actinic keratoses.” Arch Dermatol 2002 Nov; 138: 1498-502.
Swanson N, Abramovits W, Berman B et al. “Imiquimod 2.5% and 3.75% for the treatment of actinic keratoses: results of two placebo-controlled studies of daily application to the face and balding scalp for two 2-week cycles.” J Am Acad Dermatol; 2010 Apr;62(4):582-90.
Zalaudek I, Giacomel J, Schmid K et al. “Dermatoscopy of facial actinic keratosis, intraepidermal carcinoma, and invasive squamous cell carcinoma: A progression model.” J Am Acad Dermatol. 2011 Aug 10.

Actinic keratosis: Tips for managing

An actinic keratosis (AK) forms on skin that has been badly damaged by ultraviolet (UV) rays. The sun and indoor tanning expose us to these harmful rays. If you have been diagnosed with AKs, dermatologists recommend the following:

Protect your skin from the sun. By protecting your skin from the sun, you can help prevent new AKs from forming. This also will help make your treatment more effective. Dermatologists offer these tips to their patients who have AKs:

  • Avoid the midday sun. You can do this by scheduling outdoor activities for earlier in the morning (before 10 a.m.) and later in the afternoon (after 2 p.m.).
  • Slather on sunscreen every day — even on cloudy days and in the winter. Apply sunscreen to all skin that clothing will not cover.

    3 things your sunscreen must offer:

      • Protect your lips. Apply a lip balm that contains sunscreen. The lip balm also should offer an SPF of 30 or greater and UVA/UVB protection.
      • Protect your skin with clothing. Whenever possible wear:

      To see how well your clothes will protect you, hold each garment in front of bright light. If you see light through the cloth, harmful light from the sun can penetrate the cloth. You should select another garment. You also could wear that garment but apply sunscreen first to the skin that the garment will cover.

      Do not use tanning beds or other indoor tanning devices. Tanning beds and sun lamps emit UV rays that can be stronger than the rays from the sun. This can cause new AKs.

      Check your skin as often as your dermatologist recommends. If you notice a growth on your skin that has any of the following traits, contact your dermatologist right away:

      • Starts to itch or bleed.
      • Becomes noticeably thicker.
      • Remains after treatment.
      • Changes in size, shape, or color.

      Keep all appointments with your dermatologist. Left untreated, AKs can turn into a type of skin cancer called squamous cell carcinoma. With early detection and treatment, skin cancer has a high cure rate.

      Because AKs develop on skin that has been badly damaged by UV rays, you also have a higher risk for developing other types of skin cancer, including melanoma. Keeping your appointments helps to find skin cancer early when a cure is likely.

      Realize that new AKs may form. AKs form on badly damaged skin. Some people will continue to develop new AKs for life, even when they protect their skin from the sun. This does not mean that sun protection and treatment are not working.

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