Limiting Exposure to Sun More Helpful Than Sunblock

[Guest guest]

Hi, Here's article from Dermatology Times about the limits of

sunblock use.

Matija

May 15, 2002

By: Caroline Helwick

Dermatology Times

Sunscreen is super but no skin savior

New Orleans - True protection from the sun does not rely on

sunscreens but is a comprehensive plan of photo-avoidance.

And while consumers place their confidence in sunscreens, the

products are really a " crutch " for avoiding the truly difficult steps

in sun protection, such as truly limiting sun exposure, speakers said

at the annual American Academy of Dermatology meeting.

The core message should be that any sun exposure is damaging - and

sunscreens alone are not sufficient protection. Instead, people

should limit their exposure by other means, said Mark Naylor, M.D.,

associate professor of dermatology, University of Oklahoma Health

Sciences Center, Oklahoma City.

Dermatologists need to examine the manner in which they are promoting

sunscreen use to their patients. It is not appropriate to imply that

if sunburns are avoided, tanning is acceptable, he said.

" The real issue is how people are using sunscreens, " he continued.

Sunscreens should be encouraged as an adjunct to other sun protection

measures. When they are an excuse for extended ultraviolet light

exposure, the result is more UV exposure. Any exposure is

carcinogenic, and there is no safe threshold, he said.

Technical sunscreen issues

Technical issues, such as sun protection factor, are much less

significant than the manner and frequency with which sunscreens are

applied.

The problems are that sunscreens are used infrequently (they should

be reapplied 20 minutes after the first application), inadequately

(they should be liberally applied), and inappropriately (they are

used as an excuse for excessive sun exposure).

Dr. Naylor said sunscreens could, and should, be made better. While

progress has been made on technical issues, there are some lingering

concerns.

For one thing, there is little if any direct evidence in humans to

support any of the current recommendations for sunscreen use. One of

the problems is the discordance between SPF testing and actual use by

consumers, he said.

SPF is tested at 2 mg/cm2, while consumers typically apply about 0.5

mg/cm2 of sunscreen product. " This is the amount that people really

apply, and if we rated sunscreens using this number we would have a

better idea of how good they are. "

Wilkin, M.D., chief, division of dermatology and

dermatological drug products for the FDA, reinforced this opinion in

his presentation during the session. He said SPF is not, in reality,

a sun protection factor but a " sunburn protection factor " that

is " too often explained as burn time. " Consumers should not be made

to feel secure by numbers that tell them the number of hours they can

safely stay in the sun without burning, he said.

Labeling should also be more specific, instructing consumers to apply

sunscreen liberally, to reapply it frequently, and to apply it to

commonly ignored areas.

Spectral coverage is also a concern. The trend to add coverage in the

UVA range enhances the protection against photodamage and

immunosuppression, but it also poses the risk of diminished UVB

coverage.

Dr. Naylor also commented on the promotion of the UV index as

a " trigger for sun precautions. " He said that patients should be

advised to always use precautions with significant outdoor activity,

and not to ignore protection when the index is low.

Behavioral issues

Weinstock, M.D., Ph.D., chair, American Cancer Society Skin

Cancer Advisory Group and director, dermatoepidemiology unit, VA

Medical Center, Rhode Island Hospital and Brown University, described

several surveys of sun exposure and a behavior modification program.

According to a population-based survey of 1,200 U.S. youth during the

summer of 1998, the lack of sun-protective behavior is alarming. One

or more episodes of sunburn (reddening of the skin for 12 hours +)

were reported by 72 percent of the respondents while five or more

episodes were reported by 12 percent. A sunscreen with an SPF of 15+

was being used by 39 percent when they got their most serious sunburn

of the summer, Dr. Weinstock reported ( et al. Am J Epid

1999;149:565). Another survey by et al (J Am Acad Dermatol

2000) showed that 59 percent of adults had sunbathed in the previous

year.

But well-designed intervention programs can modify this behavior, Dr.

Weinstock maintained. In a study conducted by his department, the

Rhode Island Sun Smart Trial, sunbathers aged 16 and over were

approached at the beach and given an educational pitch along with

instant photographs of themselves indicating photodamage (by Woods

light images showing mottled hyperpigmentation). Other interventions

included individualized feedback by mail. At both the 12-month and 24-

month follow-up, the intervention group reported significantly

greater sun protection than the control group.

He suggested that dermatologists do more than just " give information "

to patients. " Preventive health counseling calls on you to address

the agenda, assess, advise, assist, and follow-up, " he said. DT