Sun Related Problems

Overexposure to the sun’s ultraviolet rays can have detrimental effects not only on your skin, but also on your eyes; one needs to be concerned about premature aging of the skin, with subsequent increase in wrinkling, and the possible development of skin cancer. UVB is responsible for sunburn and the development of skin cancers, while UVA is responsible for the aging changes of the skin. Sun damage is cumulative – it builds up with each exposure. Clouds do not offer total protection from sun exposure; you get sun damage in the shade if you are near reflective surfaces. Note that the number of cases of skin cancer in Canada has increased by two-thirds since 1990.

As one ages, there is a tendency to develop brownish lesions, called actinic keratoses. These skin lesions are also called solar or senile keratoses, and are precancerous growths that develop from prolonged cumulative sun damage; about 50% of people over 50 have actinic keratoses. They are potential precursors of squamous cell carcinoma (about 10-25% of them will become cancerous); they look like a rough spot which may look red or brown, and eventually become scaly, scabbed or crusted; they are most common on sun-exposed skin of pale-skinned, blue-eyed, fair-haired people. If this lesion begins to itch or bleed, it is possible that a squamous cell carcinoma is beginning to develop.

sunscreenActinic keratoses needs to be differentiated from seborrheic keratoses, which can be mistaken for cancerous growths; they feel waxy and appear to be ‘stuck on’; they also tend to appear in middle age, and do not need to be treated.

Basal cell skin cancer is the most common type of skin cancer; it grows slowly, and also appears on areas of the body exposed to sun. They tend to look like either a small bump with a pearly appearance, that may bleed, or crust over, or a red tender flat spot that bleeds easily.

Squamous cell carcinoma is the second most common skin cancer, and usually appears as a firm red bump, or a patch of skin that feels scaly, bleeds, or develops a crust; as they get larger, they can spread to nearby lymph nodes.

Malignant melanoma is a serious form of skin cancer that can quickly spread. A ‘mole’ that turns color, becoming darker brown or black, begins to grow, become irritated or bleed, requires early diagnosis and treatment.

The risk of skin cancer is higher for people who have light-colored skin, work, play or exercise in the sun for long periods of time, or who have had several blistering sunburns as a child, or a family history of skin cancer.

Ultraviolet light is the component of sunlight most responsible for eye damage, which may present itself as cataracts (clouding of the lens) or macular degeneration (breakdown of the part of the retina that focuses images); sunglasses that block UV rays are the obvious answer.

Tanning is not healthy; over time, tanned skin becomes more wrinkled and blotchy. A tan is a sign of damage to your skin; it does not protect you from sunburn. Tanning lamps emit UVA radiation and produce a deeper dermal tan, which will likely not protect against more superficial UVB effects of solar radiation.

Prevention by avoiding midday sun (from 10am to 4pm), using a sunscreen of SPF 15, wearing a hat, and if you are prone to sunburn, clothing that will cover exposed arms and legs.
Note that sunscreens are products that absorb, reflect, or scatter ultraviolet radiation; sunblocks are opaque products, which provide a microfilm barrier that blocks both UVA and UVB radiation. There is a 78% reduction in lifetime incidence of nonmelanoma skin cancers with regular use of sun protection products!

SPF = sun protective factor, an SPF of 15 allows you to stay in the sun 15 times longer than without the sunscreen before you burn; after reviewing the literature, I concluded that anything with an SPF greater than 15 was not likely to be more effective; in other words, a product with SPF 15 is adequate.

To summarize:

SLIP on clothing to cover arms and legs.
SLAP on a wide-brimmed hat.
SLOP on a sunscreen with SPF 15 or greater; look for ‘broad spectrum’, meaning that the sunscreen protects against both UVA and UVB ultraviolet rays; reapply every 2 hours, or after swimming or exercise.
Wear sunglasses with UVA and UVB protection.
Everyone needs to practice sun safety!