Definition Solar keratosis is a common premalignant skin lesion seen on areas of the body that have been exposed to sun. The lesions are not true deep or invasive skin cancers, but the area of skin is no longer normal. Premalignant means that the lesions have the 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 to grow in an irregular and unusual fashion, solar keratosis may develop.
What are the signs and symptoms of the condition? The signs and symptoms of solar keratosis include:
scaly, red patches
wart-like white, hard crusts on sun-exposed areas
tender, red raw areas that persist for months to years
What are the causes and risks of the condition? Solar keratosis is caused by long-term exposure to the sun. The number of lesions increases with age. A person with light skin has a higher risk of developing solar keratosis. Someone who works outdoors, such as a lifeguard or construction worker, is at greater risk.
What can be done to prevent the condition? Solar keratosis can be prevented using skin cancer prevention techniques. A person should limit time in the sun, especially during the middle of the day. Regular use of sunscreen outdoors helps prevent solar keratosis. Protective clothing, such as a hat and long sleeves, will also help.
How is the condition diagnosed? The doctor can usually diagnose solar keratosis by looking at the characteristic skin lesions. A biopsy may be performed to confirm the diagnosis. This involves taking a sample of the skin from the affected area and examining it under a microscope.
What are the long-term effects of the condition? A small percentage of solar keratosis lesions will become skin cancer over time. The lesions may also be painful, and they may be cosmetically embarrassing.
What are the risks to others? There are no risks to others, as solar keratosis is not contagious.
What are the treatments for the condition? Treatments for solar keratosis include:
topical medications such as tretinoin alone, or combined with fluorouracil
cryosurgery, which is the use of extreme cold to destroy abnormal cells
What are the side effects of the treatments? The medications used to treat solar keratosis may cause loss of pigmentation in the treated area of the skin.
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, and new crops of these lesions will appear over the years. The person should follow skin cancer prevention guidelines for the rest of his or her life.
How is the condition monitored? A person with solar keratosis is much more likely to have true skin cancer than most people. He or she should have regular skin checks with the doctor.
Author: Lynn West, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request