Actinic Keratosis is associated with cumulative skin damage, caused by repeated exposure to the ultraviolet light found in sunshine. Over the years, the genetic material of cells becomes irreparably damaged and produces lesions similar to the ones inthis photograph. The lesions may later become cancerous (pre-cancerous). Radiation Treatment can cause this condition.

SYMPTOMS

• Rough and dry skin lesion
• Patch or growth on the skin
• Limited to one area (localized)
• Located on the face, scalp, back of the hands, chest, or other sun-exposed areas
• Gray, pink, red (erythematous), or the same color as the skin
• Begins as flat and scaly areas
• Later develops a hard and wart-like or gritty, rough, and "sandpapery" surface -- may
  develop a horn-like texture
• The skin lesion may be easier to feel than to see.

CAUSES

Actinic keratosis is caused by sun or radiation exposure.
Risk factors for actinic keratosis include:

• Having fair skin, blue or green eyes, or blond or red hair
• Long-term, daily sun exposure (for example, if you work outdoors)
• Multiple, severe sunburns early in life
• Older age 

TREATMENT

Because actinic keratoses are precancerous changes, have them examined promptly. Follow your health care provider's advice for treatment.
Growths may be removed by:

• Burning (electrical cautery)
• Curettage and electrodesiccation (scrapes away the lesion and uses electricity to kill any remaining cells)
• Excision (cutting the tumor out and using stitches to place the skin back together)
• Freezing (cryotherapy, which freezes and kills the cells)

Growths may also be treated with medications that cause the skin to peel or come off. More recently, lasers and other light sources have been used to treat actinic keratoses.
Creams such as 5-fluorouracil and Imiquimod are used for people who have many lesions. These creams usually cause irritation and redness.

More info about Actinic Keratosis