Sunscreen

Sunscreens have been around in various forms for more than 70 years but only recently has their importance become so well known. Originally designed to prevent sunburn, they now offer important protection from many of the harmful effects of ultraviolet radiation. These include various skin cancers, photoaging, and several inflammatory conditions caused or worsened by the sun. It is common to hear that 80% of sun damage happens before the age of 18, leading many adults to forego using sun protection. This is a common misconception based on some confusion from an early study, with the actual number probably being closer to 20%. One of the most important roles in dermatology is the get our patients to understand the potential dangers of the sun and how to properly protect themselves.

Ultraviolet-A radiation (UVA) is primarily responsible for premature aging, wrinkles and tanning, while ultraviolet-B (UVB) radiation can cause burning. Both types can severely damage the skin, resulting in skin cancers. While older sunscreens were basically UVB protection, the newer generation of products also help block UVA. The introduction of avobenzone revolutionized protection against UVA in the late 1980’s, and many advances have resulted in several more stable compounds and combinations that offer excellent coverage. These products are known as chemical sunscreens, which act as filters to protect the skin from radiation. Also available, and possibly the most complete protection, are the physical sunscreens, also known as sunblock. These contain ingredients such a titanium dioxide and zinc oxide. These have come a long way since the days of the white, pasty blocks of the past. Finely micronized particles now make these elegant as well as effective, either used alone, or in combination with the chemical sunscreens.

There are some controversies regarding sunscreen use. Some studies have found sunscreen ingredients absorbed into the body. Unfortunately, most of these used non-commercial products or used very high doses, so more research is being done. There has been considerable coverage recently about the role of vitamin D and sun exposure and various types of internal cancers. Some people may benefit from oral vitamin D supplements and occasional sun exposure, but this has to be individualized for each patient.

The well known sun protection factor (SPF) has probably confused many people, since it mainly deals with only UVB protection. In the near future there will be a UVA rating system, most likely using a number of stars, to help label the effectiveness of the sunscreen against both UVA and UVB. It is wise to use a broad spectrum sunscreen with re-application every two hours, especially after swimming or sweating. Combining sunscreens with other protective measures such as protective clothing, hats, sunglasses, tinted windows, seeking shade, and avoiding midday sun all help to avoid the potentially dangerous effects of the sun on the skin.

Dr. Scott Podnos, M.D.