Don't Forget Your Sun Screen

It is well know that many, perhaps most, running injuries are problems of overuse... doing too much too fast or for too long without adequate recovery.  While not conventionally described as an overuse injury, the many hours we spend running in the sunshine exposes us to a significantly increased risk of skin damage and skin cancer. 

Runners and other outdoor sports participants face a higher risk of nonmelanoma skin cancers, like basal and squamous cell carcinoma, the two most common skin cancers.  Marathoners also show more signs of risk factors for melanoma, such as numerous small moles or any large, atypical moles.  Melanoma is the deadliest form of skin cancer, and will cause an estimated 8,650 deaths this year in the US alone.  Perhaps like me, you know at least one runner who has died of skin cancer. 

Prevention.  There are several things you can do to reduce your UV exposure and still train for your next big race:

•·         Since the sun is strongest between 10 AM and 4 PM, train as much as you can in the early morning, late afternoon, or evening.

•·         Use a water-proof sunscreen.  Apply sunscreen before putting on your running clothes.  Sunscreen needs at least 15 minutes to be absorbed by your skin before you start sweating.  Apply the sunscreen even in areas covered by your shirt (conventional t-shirts are only about SPF-7 and less than that when wet).

•·         Wear a shirt with enhanced sun protection.  Cool, wicking shirts rated at SPF-30 or greater are available.

•·         Always wear a hat and sunscreen to protect your face, neck and scalp (critical for balding males).

Checking your skin for suspicious changes can help detect skin cancer at its earliest stages.  Early detection will give you the greatest chance for successful treatment.

In March I had my annual visit to a dermatologist for a full-body inspection for signs of skin cancer.  In previous years, I've left with the usual instructions to "see us again next year and don't forget to use sunscreen."  This year was different... the doctor found some significant skin lesions on my temples, scalp and neck and thought it prudent to treat them. 

The skin lesions, technically instances of actinic keratosis (AK), also known as a solar keratosis, are rough, scaly, slightly raised growths.  They most often appear on the bald scalp, face, ears, lips, backs of the hands and forearms, shoulders, neck or any other areas of the body frequently exposed to the sun, most often in older people.   While AKs are common (an estimated ten million Americans have them), they shouldn't be ignored.  AKs are considered pre-cancers.  Studies report that 2 to 10% of untreated AKs advance to squamous cell carcinoma, the second most common form of skin cancer.

AK Treatment.  There is no way to know ahead of time which actinic keratoses are precursors of squamous cell carcinoma, so the basic strategy is to treat ‘em all.  Fortunately there are several effective treatments for eliminating actinic keratoses (see http://www.skincancer.org/treatment-options.html for details of all the options).  My dermatologist used three methods:

•·         Freezing (cryosurgery).  Liquid nitrogen applied with a spray device freezes the growths. The lesions subsequently shrink or become crusted and fall off.  My doctor tried this on the AKs on my forehead and scalp but was not satisfied with the results.

•·         Medicated cream (chemotherapy).  Carac (0.5% fluorouracil cream) is a widely used topical treatment for AKs with a reported cure rate of up to 93%.  I applied prescription cream once a day for three weeks to the sun damaged areas of my neck and shoulders.  The active ingredient in the cream selectively attacks sun damaged cells and leaves healthy cells alone.  By the end of the treatment cycle my neck and upper chest looked like I had a localized case of chicken pox.  The reddening, swelling and crusting took about two weeks to heal.  Once healed, the skin looked much better than before treatment. 

•·         Photodynamic therapy (PDT). This treatment destroys skin cancer cells with a combination of laser light and drugs that makes cancer cells sensitive to light.  My doctor used PDT for a second treatment of the AKs on my forehead and scalp.  The procedure is quick... a cream is applied to the treatment area, you sit in a darkened room for a hour while the cream is absorbed and then the treatment region is exposed to a very bright light for 1000 seconds (just under 17 minutes).  Then you are sent home with instructions to avoid direct sunlight for a couple days.  The treated area looks and feels like bad sunburn for a few days.

Following the treatment experience, I am being a lot more rigorous in my sun protection.  I especially like the Outdoor Research Sun Runner (pictured on the right) for the its nice balance between protection and coolness. 

My followup visit with the dermatologist will be in early July.  If you're curious about how it turns out, check back after July 10th.