Sunscreen Information

[Guest guest]

The summer 2002 issue of " Lupus News " has several VERY good articles on skin

and sun.

(2 Lupus Websites - http://www.lfaga.org/ or www.lupus.org)

Below is some of the information from the artilces.

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In general, UVA ages the skin and UVB burns the skin (i.e. " A ages, B

burns " ).

The sun protection factor (SPF) is a number that is calculated by dividing

the light sensitivity without sunscreen by light sensitivity with sunscreen.

The higher the SPF; the more protective the blocking agent is. However

there is no similare method of labeling sunscreens for theri protection

against UVA. The use of broad spectrum sunscreens (covering both UVA and

UVB) should therefor be used.

Because car windows and clouds only protect against UVB, not UVA, sun

protection should not be limited just to sunny days.

Sources of UV light other than sunlight can also cause skin problems in

lupus. Photosensitivity in lupus has been reported with florescent tube

lights, which may emit UVB, and photocopiers, which emit maily UVA.

Fluorescent tubes may be fitted with acrylic shields, which elimiate UVB

emission.

The long-wavelenth ultraviolet A, or UVA is 1,000 times less effective in

causing sunburn than UVB, but it is more plentiful and penetrates more

deeply into the skin. UVA also speeds skin aging by damaging collagen, the

fibrous protein found in skin and other tissues.

If skin reddens in 10 minutes without sunscreen, it will redden in 150

minutes when protected by an SPF-15 sunscreen and in 300 minutes with an

SPF-30 sunscreen.

A very high SPF number gives people a flase sense of security: they don't

burn, so there is nothing warning them to get out of the sun.

As the SPF number gets higher, the differences in protection get smaller and

smaller. So, for exampl;e, the difference in the amount of sunlight kept

off the skin between and SPF-30 and an SPF-50 sunscreen is just 1.3 percent.

Keep in mind that SPF is based on the use of a set amount of sunscreen - 2

milligrams per square centimeter of skin. That works out to a bit more

thatn an ounce for a 5 ft 8 In person per application. Most people use half

to a quarter of that amount, however, and at those levels an SPF-15

sunscreen has an SPF of just 3 to 7. Consider this: to get the full SPF

value out of suncreen, a family of four should be using an entire 4-ounce

bottle during a day at the beach - even more if they are spending a lot of

time in the water.

The upshot of this research is that when you shop fro a broad-spectrum

sunscreen, it is probably best to look for one that contains zinc oxide,

titanium dioxide, or avobenzone. But even these 3 ingredients have

drawbacks.Some researches suggest that avobenzone might degrade with exposed

to UVA, the very thing it is supposed to protect against. Ainc oxide and

taitanium dioxide are white and can make sunscreen milky. Zinc oxide was

found, in one recent study, to be less visible and more protective than

titanium dioxide.

To qualify as " water resistant " , a sunscreen must retain ists SPF rating

after 40 minutes in the water. The standard for a " waterproof " lable is 80

minutes.

Enough people react to an ingredient callled PABA to create a significatn

market for PAB-free formulas. People with rosacea might want to steer clear

of padimate-o because it is irrating. Zinc oxide and titanium dioxide are

not absorbed by the skin and are rarely irrating.

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