Sunscreen 101

Sunscreen 101

One of the most common questions I get, both year-round and especially at this time of year as summer approaches, is on sunscreen use and which product(s) to use.

The short answer, for anyone over 6 months of age, is ANY SUNSCREEN YOU LIKE WITH SPF> 30 AND WILL USE REGULARLY.

The long answer is below:

Here is some background information on sunscreens for review. Sunscreens are divided into physical sunscreens and chemical sunscreens. Many products combine ingredients to more effectively block UVA and UVB as different compounds may be more or less effective against UVA and/or UVB.

Physical sunscreens:
- aka inorganic sunscreens
- includes zinc oxide and titanium dioxide
- work by physical blocking or reflecting the sun's rays
- tend to be white or shiny or a little heavier, although new "micronized" formulas have improved this

Chemical sunscreens:
- aka organic sunscreens (this is confusing to many and is not the same as 'organic' meaning natural or less processed)
- include all "tongue-twister" ingredients like ecamsule (Mexoryl SX and XL), octylcrylene, octylmethoxycinnamate, cinoxate, avobenzone (Parsol 1789), octinoxate, octisalate, oxybenzone, homosalate
- work by absorbing ultraviolet light

UVA radiation accounts for 95% of all ultraviolet light reaching the Earth. UVA is the predominant tanning rays, and has long been associated with photo-aging (I remember "A" for aging) and sun damage. It is what most tanning beds use as well. It doesn't vary much with time of day, season, or location. It penetrates glass as well as cloud cover. UVA penetrates deeper into the skin and has more recently been linked to the development of skin cancers as well as sun damage and photo aging.

UVB radiation causes sunburn and skin reddening, also known as erythema. It tends to penetrate less deeply than UVA and has been strongly associated with the development of skin cancers. It also plays a supporting role in tanning and sun damage and photo aging. Think "B" for burning and bad (i.e. skin cancer). It is blocked by glass and varies by season, time of day and location.

SPF refers to "sun protection factor" and is a measure of UVB protection only. In the USA, there is currently no standard by which UVA protection is measured or indicated on a product label. That may change soon in the future but currently UVA protection is indicated by the words "broad spectrum" on a label. Generally most commercial sunscreens do offer good UVA and UVB protection.

So getting back to the question, "What sunscreen should I use or put on my child?"

The best protection is prevention:

Avoid intentional sun exposure and tanning.

I LOVE sun protective clothing. It is safe, it is effective, and it is economical and doesn't need to be reapplied. You can now get sun protective clothing in many stores and on-line. Some of my favorite sites are Solumbra or SunPrecautions (http://www.sunprecautions.com/)and Coolibar (http://www.coolibar.com/).

I would use at least an SPF 30 or greater.

Children < 6 months of age:
- ideally do not expose infants to excessive sunlight, especially between 10 and 4 in warmer months
- rely primarily on hats and sun protective clothing and seek shade
- if you must apply sunscreen to an infant, use the physical blockers such as zinc oxide and titanium dioxide
Note: some sunscreens labeled "baby" are not physical sunscreens but checmical ones and I would avoid them until > 6 months of age

Patients with multiple allergies or very sensitive skin:
- try a product with fewer ingredients
- try products labeled for sensitive skin or babies and avoid 'sport' formulas
- try titanium dioxide and/or zinc oxide, the physical blockers
- before using a new product, do a skin test on yourself by applying a small amount of the product daily for 7-10 days (I recommend on the inside of the arm) and make sure you don't react. If you do, take product back. Most stores will give you a refund and I know sunscreen gets expensive!
- there is a product line called Vanicream that makes skin care products without dyes, fragrance, masking fragrance, parabens, lanolin and formaldhyde, and has two sunscreens (SPF 30 and 60) that are physical blockers only.

> 6 months old through adulthood
- whatever product you or your child likes and will apply and reapply
- I like sprays for children, especially the new products that you can apply to wet skin (Aveeno and Neutrogena), just try not inhale the spray and make sure if you are applying it outside with a breeze that you are getting a good application
- there are alcohol based products and lighter oil-free products for men or people with acne
- many face products exist and tend to be less irritating, especially around the eyes
- I like stick sunscreens (Banana Boat, Neutrogena, Clinique) for kids and for around the eyes and lips

A few reminders though. No sunscreen even if labeled waterproof or sweat-proof or long-lasting can be expected to last longer than 2 hours. You must reapply every two hours or sooner after swimming, heavy sweating, towelling dry, etc... Most people don't apply enough or reapply often enough. For an adult, a whole body application is 1 ounce = 1 shot glassful = 1/4 of many sunscreen bottles. One bottle of sunscreen should not last you much longer than one day at the beach, let alone all summer!