Actinic Keratosis

Actinic Keratosis

Actinic keratoses (AKs) are considered the earliest stage in the development of skin cancer. They are common lesions of the epidermis (outermost layer of the skin), and are caused by long-term exposure to sunlight. It is most commonly found in fair-skinned people because their pigment isn’t very protective.

Chronic sun exposure damages the skin cells in AKs called keratinocytes. They are the cells that make up 90 percent of the epidermis and give the skin its texture. With the changes in keratinocytes, the skin becomes rough, scaly, or mottled, and develops papules or small horn-like growths. Further changes in cell growth can allow AKs to progress to squamous cell carcinoma, a type of skin cancer.

What does Actinic Keratosis look like?

Actinic keratoses are found on chronically sun-exposed skin, most commonly on fair-skinned people. They are commonly found on the sides of the forehead, the ears, the scalp of bald men, and the backs of the hands. The typical AK lesion is a dry, scaly, and rough skin-colored to reddish-brown “bump.” AK lesions may range from the size of a pinhead to larger than a quarter. Skin-colored AK lesions may be noticed by the touch and feel like sandpaper.

Sometimes the skin cells making up an AK lesion undergo abnormal growth and become a “cutaneous horn.” The cutaneous horn gets its name from its appearance (it can look like the horn of an animal). The size of a horn may vary from a pinhead to a pencil head eraser and its shape may be straight or curved. The external ear is a common site for cutaneous horns.

How is Actinic Keratosis diagnosed?

AKs have unique physical characteristics that allow dermatologists to visually identify them. However, if an AK is especially large or thick, the lesion may be surgically removed for microscopic examination (biopsy) to determine if squamous cell carcinoma is present. When an AK is diagnosed, physicians consider a number of factors before choosing the most appropriate treatment method. Factors include:

  • Size, number, location, and stage of the lesions
  • Age, health, and medical history
  • Occupation
  • Cosmetic expectations and treatment preferences
  • Patient compliance (i.e., willingness to self-treat as needed for several weeks)
  • History of previous treatment

How is Actinic Keratosis treated?

  • Surgery
  • Local destruction
  • Topical Chemotherapy
  • Local Immunotherapy

How to prevent Actinic Keratosis

Prevention of AKs should begin early in life. Sun damage to unprotected skin begins in childhood and puts the child at risk for actinic keratoses and skin cancer later in life. However, it is never too late to initiate prevention of new actinic keratosis lesions in adulthood.

Basic precautions are:

  • Seek shade during peak sunlight hours (10 a.m. to 4 p.m.)
  • Wear clothing that covers arms and legs, and wear a wide brimmed hat
  • Use a sunscreen with a sun protection factor (SPF) of 15 or higher daily, and apply it at least 20 minutes prior to sun exposure for maximum sun protection
  • Select a broad-spectrum sunscreen that provides both UVA and UVB protection, and reapply sunscreen every 2 hours when outdoors, even on cloudy days