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Posts Tagged ‘actinic keratoses’

Do Sunscreens Cause Cancer? Are they safe? Notes from a San Francisco Bay Area Dermatologist

Tuesday, July 13th, 2010

The latest question on patients’ minds this summer is the safety of sunscreen.  A few websites have posted articles scaring people into questioning whether or not they should use sunscreen.  The bottom line is that sunscreens protect us from skin cancer and here’s why:

What do we know?

Numerous studies have looked at this issue, and none have confirmed any link between sunscreens and skin cancer. Some researchers have speculated that since sunscreens allow users to stay out in the sun longer they may increase the risk of skin cancer.  There have also been worries about physical sunblocks zinc oxide and titanium dioxide nanoparticles (micronized).  The worry is that these may pose a danger if inhaled or absorbed through the skin.  A large National Institutes of Health (NIH) funded study found minimal skin absorption of titanium nanoparticles and this has been confirmed by other studies.  It is possible that inhaled nanoparticles may be risky.  So if you use a spray sunscreen keep it away from your face (spray on your hand and rub in) or hold your breath when you spray.

We do know that the sunscreens help prevent skin growths called actinic keratoses.  These are rough scaly patches that can develop into squamous cell cancer.  There  is less evidence that sunscreens protect against melanoma and basal cell cancer.  This may be because these two cancers are strongly linked to sunburn.  Your risk of melanoma doubles if you have had five or more sunburns at any  age or from just one blistering sunburn before the age of 20.  Basal cell cancer seems also to be linked to  the  amount of freckling and number of burns.  In other words excessive sun exposure definitely causes cancer!!

Given that we know the sun can cause cancer and the evidence is nonexistent that sunscreens cause cancer common sense should prevail. Use sunscreen!

Are sunscreens safe for the environment?

Unfortunately sunscreens are bad for the ocean environment!  They come off in the water and settle down to the coral reefs blocking vital UV radiation. What can you do?  I am a huge proponent of  light weight wetsuits and  UV protective rash guards used for surfing.  I always wear one when I snorkel or windsurf. It is easier to put one of these on your kids and yourself than to deal with suncreening your whole body and reapplication after swimming.  They come in cute colors and styles and are widely available.  You can bolster their UV blocking abilities by washing with SunGuard or a similar product.  They claim they are effective up to 20 washing  cycles or swimming dips!  Apply your sunscreen to your face and hands and cover up  the rest with UV protective clothing!! You save your skin and the ocean!

 

Derm Terms: Notes from a San Francisco Bay Area Dermatologist

Sunday, March 28th, 2010

In dermatology, there are lots of terms for various spots and lesions that may appear on the skin.  These terms can be confusing, especially if you aren’t sure which are the “bad” kinds and which are less of a worry.

One of the most common terms is actinic keratoses or AKs, which are most often seen on the face, ears, lips and backs of hands, but can appear on any sun damaged area of the skin.  AKs are spots where the top layer of skin is dividing too rapidly.  They usually show up as a dry, scaly and rough textured patches of skin.  They may be brownish, red or flesh colored.  Some may even be crusty..

AKs tend to arise more frequently after age forty, but if you are fair skinned with light colored eyes and have had average to heavy sun exposure they may appear earlier.

AKs are also called “precancers” because if left untreated, they have the potential to progress into squamous cell carcinoma, a potentially deadly form of skin cancer.  Because of this potential, it is important to have any AKs treated as they come up.  Cosmetically, they make the skin appear more aged and makeup doesn’t cover them very well.

Treatment may include cryosurgery (freezing the spot with liquid nitrogen), numbing the area and scraping the lesion off or use of a prescription cream that targets the damaged cells and destroys them.  Luckily, most AK treatments are fairly inconspicuous and the recovery time is minimal.  For more extreme cases or areas where there are too many precancers to treat individually, we may use PDT or photodynamic therapy treatment.  This process involves a light microdermabrasion to the skin, followed by the application of a chemical that is activated by a laser to eradicate the errant skin cells.  This treatment requires you to stay indoors 24 hours afterward.  The result is skin that will look, feel and be much healthier.

To prevent AKs and skin cancer, sun safety is always your best bet.  Always apply and re-apply sunscreen to exposed areas of skin and do your best to stay out of the sun!

I can never say enough about the benefits of topical retinoids like Retin-A, Refissa, Atralin or Retin-A Microgel, but yet another positive point is that they can actually help the skin ward off AKs.  Their exfoliating properties keep these damaged cells from taking hold and help the skin stay smooth.

As always, if you notice any new spots or moles that have changed, have a dermatologist look at them for any potential issues.  Be sure to check in with the blog as more derm terms will be discussed!

 

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