Understanding Sunscreen

Skin CareLiving in Bend, Oregon, with the combo of high altitude and a ton of sunny days, we’re all exposed to a lot of sun. The sun’s ultraviolet rays are the stinkers, penetrating the skin and damaged its cells, leading to skin aging and wrinkling, and various skin cancers.

We all know that the best thing would be to never go outdoors, unless we are dressed like a mummy. But when you live in a recreation wonderland like Bend, who wants to do that?

So, we all apply sunscreen. But what do you really know about sunscreen and how it protects, or doesn’t protect, you? Here’s some info.

Sun protection factor (SPF) and UV radiation

Since the advent of modern sunscreens, a sunscreen’s efficacy has been measured by its sun protection factor, now commonly known by its acronym, SPF. SPF is not really a measure of protection, it is a measure of how long it will take for ultraviolet B (UVB) rays to redden your skin compared to having no sunscreen on. For instance, SPF 15 means that it will take 15 times longer with sunscreen on than without. Why does it use the UVB rays? Those are the rays that cause sunburn because they penetrate only the epidermis, the surface layer of the skin.

As for amount of UVB protection, an SPF 15 sunscreen screens 93 percent of the sun’s UVB rays; SPF 30 protects against 97 percent; and SPF 50 protects against 98 percent. The U.S. Department of Health and Human Services recommends only SPF 15 and higher for providing adequate protection.

But scientists now say UVA rays, which penetrate far more deeply, into the dermis layer of the skin, also cause skin damage and skin cancer. So, you need a sunscreen that protects against both UVA and UVB. To do this, look for a sunscreen with at least SPF 15, plus some combination of the following UVA-screening ingredients: avobenzone, ecamsule, oxybenzone, titanium dioxide, and zinc oxide. When you see a label that says broad spectrum or multi spectrum or UVA/UVB these indicate that some UVA protection is provided. However, there isn’t a measure of how much protection these terms denote.

How do sunscreens work?

The ingredients in sunscreens form a thin, protective film on the surface of the skin and absorb the UVA radiation before it penetrates the skin. The “sunscreens” are actually physically screening the sun, meaning that their insoluble particles reflect the UV rays back off the skin. The FDA has approved 17 active ingredients for use in sunscreens.

Unfortunately, no matter how much you know about UVA rays and sunscreen, your skin will still suffer sun damage. Trust the experts at Deschutes to care for those problems once they hit. Call us to have your skin checked regularly, 541-330-0900.

Dealing with Skin Cancer

Skin CancerSkin cancer is the most common form of human cancer. Why? Because it is mainly caused by exposure to the sun’s untraviolet rays. And, unless you’re a vampire, humans spend lots of time out in the sun.

Three types of skin cancer

Melanoma — The M word of skin cancer, melanoma forms in the melanocytes where skin pigments are produced. Melanoma is far and away the most serious type of skin cancer because it easily spreads to other parts of the body.

Basil cell carcinoma — Basil cell carcinomas form on the outer layer of the skin, the epidermis. If caught early, this type of skin cancer is easy to remove.

Squamous cell carcinoma — This forms in the squamous cells, the flat cells on the surface of the skin. Like basil cell carcinomas, if detected early, these are very easy to remove.

Treating skin cancer

There are different methods for treating skin cancer, depending on the type and severity. At Deschutes, we aim to remove or destroy the cancer with the least possible scarring. Here are some of our methods:

  • Curettage and desiccation — The cancerous growth is scooped out of the skin with a curette.
  • Surgical excision — the cancerous area of the skin is cut out with a scalpel and the area is closed with stitches.
  • Cryosurgery — Abnormal cells are frozen with liquid nitrogen. This is usually used on pre-cancerous cells that could become cancerous.
  • Mohs micrographic surgery — Cancerous tissue is removed along with minimal adjacent tissue. The tissue is then examined under a microscope to see that all of the cancerous cells have been removed. If not, another ring is removed a bit further out, and the examination is repeated.
  • Creams — a newer approach that triggers the body to attack itself, creams are applied to the cancerous area, inflaming the skin and triggering the body to send white blood cells to attack the inflammation. If successful, the white blood cells eliminate the cancerous cells.

If you have spots or moles on your skin, particularly if they change shape or color, these could be skin cancer. Make an appointment with us at Deschutes Dermatology and let’s take a look. Call us 541-330-0900.