Solar Keratoses
Known as ‘Sun Damage’
Solar Keratoses are the white, scratchy lesions that appear on sun exposed skin areas as we age, often appearing in our 40s in fair skinned, red headed, blue eyed people and increasing in number as we age. Solar keratoses can cause irritation, discomfort & itch and can bleed when scratched. These lesions were once thought to be ‘just sun damage’ but we now know that they have the potential to change into Squamous Cell Carcinoma (SCC) which can spread around the body just as a Melanoma can. For this reason, it is important that they are properly diagnosed and actively treated as SCC is more common in Australia than Melanoma.
Traditionally solar keratoses were treated by freeze burning them off with liquid nitrogen. This is still used today but the lesions seen clinically are estimated to represent only 10% of the actual lesions present, ie we can miss 90% of solar keratoses using liquid nitrogen alone. Often patients will have large areas such as the whole face & scalp as well as the forearms needing treatment hence it is not practical to freeze such a large area (and can also be very painful). For this reason, new treatments were developed and are known as ‘Field treatments’ because they allow the treatment of a much larger area (field) and treatment of lesions that cannot be detected clinically. Commonly used examples are the topical creams AdlaraTM, EfudixTM, Solareze TM and Photodynamic therapy. These creams treatment differ in duration of treatment and expense but have similar side effects.
Field treatment involves applying a topical cream to the sun damaged area from 4-6 weeks. The cream is selectively taken up by the abnormal cells which results in death of these cells without damage to the surrounding normal skin. This can result in redness, discomfort, irritation, and sensitivity to the sun. Despite the side effects patients report their skin quality improves as well. Field treatment is usually prescribed in the cooler months when the UV index is low and strict sun protection is recommended.
If you are concerned about sun damage and your risk of developing skin cancer March is a good time to plan a skin check to allow accurate assessment & diagnosis and time to plan any treatments needed over the Winter months.
Dr Jane Sheedy
BSc BMBS FRACGP DRANZCOG MMED skin cancer