All the Answers about Sunscreen: Why? Which one? How much? How do I pronounce Octocrylene?

little cute girl near the pool with a circle for swimming

Octocrylene. Octo (like the lady with 8 kids) – cry- lean.

Hmm.

Sunscreens have been around forever, mostly in the form of plants and dirt people rubbed onto their skin. Not terribly effective, sadly. Ancient Egyptians used aloe vera, extracts of rice, and pounded out calcite and clay to protect their skin. In the Philippines borak was used – made from water weeds, rice and spices. Zinc oxide has been around for thousands of years.

The first synthetic sunscreens were created in the 1920s, and were made commercially available by L’Oreal in 1936.

Sunscreen became more popular after WWII, when we sent a bunch of pale skinned soldiers to the Pacific Islands. Ouch.

These original sunscreens are estimated to have had an SPF of about 2. Also not terribly effective.

 

Why do we use sunscreen?

We use sunscreens to prevent sunburn, skin cancer, wrinkles, and hyperpigmentation.

The incidence of melanoma has increased in the 15-39 year age range by 3% per year since the 90’s. It is the 2nd most common cancer for women in their twenties, 3rd for men. Dr Sophie J. Balk (Former Chairperson, AAP Committee on Environmental Health) writes that this was caused by the thinning ozone layer, the fact that people are wearing less clothing, intentional tanning, and tanning beds.

Skin cancers like squamous cell carcinoma, melanoma, and possibly basal cell carcinoma can be prevented by using sunscreen – if you use the right one in the right way.

 

Who should use sunscreen?

Everybody.

It is especially important for children and people with fair skin, fair eyes, freckles, sun sensitivity, moles, or a family history of melanoma.

But really, everybody.

 

The Science: What Does the Damage?

Sunlight has wavelengths between 290-3200 nm; the light that we see, or “visible light” runs between 380 to 740 nanometers. Wavelengths in the top, violet part of the rainbow are 380-450 nm, so the wavelengths shorter than violet are called “Ultraviolet.”  UVB rays are the 290-320 range (about 5% of the total); UVA rays are 320-400 (95% of the total).

UVB rays burn, leaving you with redness and pain, and these were traditionally the rays we tried to block. UVB does contribute to skin cancer but since it does not penetrate as deeply as UVA it seems to not be the cause of the most deadly of skin cancers, the melanomas.

UVA light does not cause reddening or pain, and most conventional sunscreens do not block it. It does however penetrate deeply into the skin to cause the damage to DNA in cells (melanocytes) that can lead to melanoma.

UVB is more intense midday (from 10AM – 2PM), in the summer, closer to equator, and at high altitude. UVA light is constant through the day and year.

Window glass absorbs UVB, not UVA.

Both reflect off water, sand, snow, and concrete to increase exposure.

UVB and UVA penetrate water to a depth of about 60 cm (about 3 feet).

 

How to protect yourself from these evil rays?

Best, of course, is to avoid them. Stay out of the sun, especially between 10AM and 4PM.

Cover up. Light weight, long sleeved shirts and long pants are protective while they are dry. There is a UPF rating for fabrics, from UPF 15-50. Above 30 is considered sun protective, and more is better. There are swim shirts for kids that are protective even when wet.

Wear a hat with a brim.

Wear sunglasses with 99% UR protection.

Use sunscreen. Sunscreens absorb or reflect the sun’s ultraviolet rays, depending on the ingredients.

  • Sunscreens come in lotions, gels, or sprays.
  • They generally last about 3 years on the shelf.
  • SPF should be 30 or higher.
  • The words “broad spectrum” should be on the label, since only these have UVA protection that is proportional to the UVB protection.
  • The only chemical sunscreens available in the US that protect from UVA are avobenzone (which can be irritating and allergy producing) and Mexoryl SX and XL, available only from L’Oreal (they have a patent). Outside of the US, Tinosorb S & M and Uvinul A Plus block UVA. Mineral sunscreens also block UVA.
  • Look for “water resistance” on the label as well, especially if you will be swimming or sweating.
  • Apply sunscreen 20 min before exposure so that it has time to form a thin, even, protective film.
  • Apply 2 mg/cm2: this is about 2 tbsp for the average adult (about a shot glass, per the Dermatology Association), and about 1/4 tsp for the face. If you put on less, you get proportionately less protection.
  • Reapply sunscreen every 2 hrs or if you sweat, swim, or rub it off; stronger sun screens do not last longer and while newer sunscreens are very photostable, they do still rub off.

Sunscreens come in two basic forms, and combinations of the two forms.

Mineral (physical, inorganic) sunscreens include zinc oxide and titanium dioxide. They are usually better for sensitive skin, but they can leave a white cast and tend to be thick. They work more by reflecting sunlight, although they do absorb some. They do block UVA as well as UVB – zinc oxide more effectively than titanium dioxide.

The second type is Chemical or Organic sunscreens. They apply more like moisturizer and don’t leave a white cast. They work by absorbing sunlight’s high energy rays, although they do scatter and reflect some in the same way as mineral sunscreens.

Common Chemical/Organic sunscreens in the US:

  • P-Aminobenzoic acid
  • Padimate O
  • p-Aminobenzoic acid
  • Cinoxate
  • Dioxybenzone
  • Oxybenzone
  • Menthyl anthranilate
  • Octyl methoxycinnamate
  • Sulisobenzone
  • Trolamine salicylate
  • Avobenzone
  • Octocrylene
  • Octyl salicylate
  • Ecamsule
  • Homosalate
  • Mexoryl SX & XL

Common questions about sunscreen:

For much of this information I have to thank LabMuffin, because I am no chemist. She is a PhD chemist who educates on the chemistry behind skin and beauty products. She is amazing, and I highly recommend checking her out!

Don’t kids need sunshine to make vitamin D?

Yes, but they only need 5-30 minutes in the sunshine about twice a week, depending on their skin tone. Also, vitamin D is in milk and comes in pill form.

Should we worry about nanoparticles from mineral sunscreens?

The nanoparticles made from grinding up the mineral sunscreens (so they don’t look white on the skin) are too big to penetrate the stratum corneum and get to live skin cells.

What ingredients are the most irritating or allergic?

  • Avobenzone
  • Octocrylene
  • Oxybenzone
  • PABA
  • Padimate O
  • Enzacamene

Which ingredients are the least likely to break down in sunlight?

  • Tinosorb S and Tinosorb M (not in the US yet, hopefully soon!)
  • L’Oreal’s Mexoryl SX and Mexoryl XL
  • Mineral sunscreens

But don’t sunscreens have hormonal effects?

Yes, some of the chemical/organic ones do, but very little. One of the worst is oxybenzone, and to have a hormonal effect we would have to use it continuously for 277 years. Enzocamine, Padimate O, octinoxate, and homosalate also have hormonal effects in minuscule amounts.

Don’t some medicines make people react more to sunlight? 

Yes. A short list of meds on which you should avoid sunlight:

  • NSAIDS (ibuprofen, naproxen)
  • tretinoin (retinols)
  • tetracyclines
  • phenothiazines
  • psoralins
  • sulfonamides
  • thiazines

Aren’t there plants that make people burn more easily?

Yes. Plants that produce furocoumarins, like limes, can cause a burn and hyperpigmentation when exposed to sunlight.

Can I use a sunscreen/insect repellent combination product?

The AAD recommends purchasing and using these products separately — sunscreen needs to be applied generously and often, whereas insect repellant should be used sparingly and much less frequently.

Are sprays safe and effective?

Current FDA sunscreen regulations do not apply to sprays, so I don’t know. They should not be used near heat or open flame (no smoking!), and should not be inhaled.

What will the UV index for tomorrow be? Check out www.weather.com.

 

What those labels mean:

SPF stands for “Sun Protection Factor,” and measures sunburn producing UVB rays. The number is how much burning radiation penetrates through the sunscreen. An SPF of 20 means that 1/20th of the rays reach the skin. Above an SPF of 50 you don’t see any real difference.

SPF Equivalence requires UVA protection of at least 1/3 the SPF for UVB. This labeling is seen more in Europe.

PPD is “Persistant Pigment Darkening.”

Star ratings are used in UK and Ireland, between 1 and 5 stars.

PA is “Protection Grade of UVA”, used in Asia, between PA+ to PA++++.

If “Water resistance” is on the label, it should say whether it is resistant to swimming or sweating and for how long.

 

If you can, please share this blog. The sun is shining outside and sunscreens can be very confusing!

 

Doc’s Top Tips To Prevent Summertime Injuries

little cute girl near the pool with a circle for swimmingSafety is not simple.

There is no clear division between “this activity will be safe,” and “this activity will injure my child.” We could wrap our children up, keep them indoors, and not allow them to play with anything remotely dangerous—but then we would have a child who is lonely, overweight and really bored…who would get into trouble and injure themselves… Or not get in trouble and develop diabetes, heart disease and knee problems from obesity.

Kids need to be active, and summertime brings many interesting opportunities for exercise, adventure and injury.

Wouldn’t it be great if some doctor type person would tell you what activities were the most likely to bring ER bills into your life?

Oh, wait… That’s me! So:

The most common causes of accidental death are gunshots, motorized vehicle and bike accidents, drowning, poisoning, and fire.

Drowning, MVAs, bike accidents, and trampoline accidents are all more common in the summer, when kids are out of school.

Water Safety

Drowning is every pediatrician’s worst nightmare. It is currently the fifth leading cause of accidental death. An average of 700 children drown each year: about 2 each day. Most are under 4; 80% are male. For every death, there are 5 more children who drowned but survived, commonly with irreversible damage to their brains.

Infants and toddlers drown in bath tubs, buckets, toilets–it only requires about an inch of water, just enough to cover their nose and mouth. Older children drown in pools, rivers, lakes, and oceans.

Never leave any child alone for even a moment near open water, whether it is an ocean, a bathtub, or a water bucket. All it takes is one moment of inattention for a child to slip away. If there is open water, you need to be within touching distance and focused on your child. The story I have heard over and over is, “We were right there, just talking, but nobody noticed anything until we realized he was gone.” Keep your kids in sight, and don’t let yourself get distracted.

Be especially careful at the end of the day, as the water empties and people are gathering up their belongings and leaving. Children will want to swim just a minute more, or will attempt to go back for that last toy floating in the water.

Pools should be fenced in and closed off with a self-latching gate at the end of the day, and all the toys should be put away. Life vests are fabulous for a parent’s mental health and relaxation (swimmies and floaties are not life jackets). Life preservers and a shepherd’s crook should be placed obviously nearby wherever kids are swimming.

Sign your kids up for swimming lessons, even if you are afraid. A middle schooler or teen will never admit to their friends that they don’t know how to swim. They will fake it, sometimes unsuccessfully. Don’t, however, trust a young child to remember his or her swimming lessons when they need them. If they are startled or scared, they will forget everything they learned and just sink to the bottom.

Know what to look for. In real life, drowning does not look like it does in the movies. It is possible to miss someone drowning right in front of you if you do not know what you are seeing. They do not shout for help and wave their arms. They tire, and panic. A drowning child might never make a sound, but quietly slip under the water. An older child might keep themselves above the water for a while, but their head might be low in the water, with their mouth at water level, or perhaps with their head tilted back. Their eyes might be blank or closed. They will sometimes hang vertically in the water without paddling their legs, or appear to paddle with no purposeful movement. A drowning person is very easy to miss if you are not vigilant; and very easy to help if you are.

Somebody should know CPR—why not you? Your local fire department or hospital will have classes.

Swimming is a necessary skill, fun, and excellent exercise; it is also a time for close observation and care.

Motorized Vehicles

The other motorized vehicles—ATVs, dirt bikes, snowmobiles, and Sea-Doos—are also commonly out in the summer. They are the perfect storm: they go fast, have no outside framework, roll over easily, and the only things that keep them from crashing are your children’s foresight, common sense, and trained reflexes. Hmm. The United States averaged 23,800 dirt bike crashes requiring emergency room visits every year between 2001 and 2004; these numbers go up as dirt bikes become more popular. Don’t. Really, just don’t.

You do like the kid, right?

Bikes

Bikes come out of the garage when the weather warms up and the roads are not covered in ice. And yes, the dorky bike helmet is an excellent idea.

Thousands of children are injured or killed every year due to bike accidents, frequently right near their homes. In 2010 alone, there were 800 deaths, 26,000 traumatic brain injuries and 515,000 emergency room visits after bike accidents.

Asphalt is not soft, even right next to your house. When a car hits a child, the child flies through the air. The heaviest part of the child—the head—lands first.

Make them wear the dorky helmet, on top of the head please, covering the top of the forehead, and tied snugly under the chin, not dangling on the back of the head. Hang it on the bike handlebars when not in use so that it is the first thing on and the last thing off. Keep a big lock handy so that if you catch them on the bike without the helmet, you can lock it up and they can walk for a week. Sorry kid, that was the rule and you knew it. There is no need for any argument.

Please don’t buy a bike two sizes too big. Your child will fall off. Children should be able to place the balls of their feet on the ground while their rump is on the seat, and their whole foot should be flat when they are standing over the crossbar. An extra bike or two over the years is cheaper than a broken child.

Trampolines

Trampolines are a huge source of income for surgeons and orthopedists. If you would like to make them poor, don’t buy a trampoline. If you have one, please be careful. Most trampoline accidents occur when there is more than one person on the trampoline, especially when they are not the same size. The smaller one goes flying or is fallen upon. Safety nets and pads are better than no safety nets and pads.

On second thought, forget I said all that. Let’s go back to no trampolines. Kids break bones, damage their kidneys, and hurt their heads and spines.

Children will at some point injure themselves because they need to be free to run, swim, and climb monkey bars and trees. Try not to obsess over scraped knees, a goose egg on the forehead, or a few stitches. Everybody gets those, and your children will find a way.

Concentrate on the risks that will kill them or seriously injure them: motor vehicle accidents, drowning, fires, poisonings, and gunshots. Don’t go out of your way to buy things that will hurt them, such as trampolines and ATVs.

Make it so they have to get creative if they want to injure themselves. Creativity is good, right?