Summer time is fast approaching, and although here in St. Louis glimpses of the sun recently have been far and few between, sunny days will return to us eventually. Although the use of sunscreens shouldn’t be reserved for just sunny, summer days, this is definitely the time of year when they are foremost in most people’s minds. Of course, if your concern includes the prevention of premature aging skin, you probably think about sunscreen year round, because UVB/UVA radiation is the primary preventable cause of aging skin.

To protect your skin from both types of radiation (UVB and UVA), a sunscreen must contain a combination of organic (chemical sunscreen ingredients) and inorganic (physical sunscreen ingredients) filters. Combination sunscreens enhance the SPF of the final product.

Chemical sunscreen ingredients act as an ultraviolet sponge to absorb damaging UV rays. The chemical reaction of the UV rays with the chemical sunscreen ingredient creates heat, which is why some people experience “feeling hot” when using sunscreens. Physical sunscreen ingredients deflect or block damaging UV rays in a similar fashion to protective clothing.

Current toxicology based on acute and chronic exposure to (UVB/UVA) broad-spectrum sunscreens concluded that sunscreen ingredients or products pose no human health concern, despite what may be reported in the media. What is a positive, as well, is that micronized, transparent zinc oxide is not absorbed into the skin; and there are no reports of skin allergies to zinc oxide.

Most dermatologists would agree that the use of sunscreen has contributed to a decrease in the incidence of photo-damage and pre-cancerous skin lesions. In fact, the American Academy of Dermatology recommends that, regardless of skin type, a broad-spectrum sunscreen with an SPF of at least 15 should be used year-round. Patients must understand that sunscreen shouldn’t be reserved for use only on sunny days. Seventy percent of the sun’s ultra-violet rays can pass through the clouds. Additionally, sand reflects 25 percent of the sun’s rays, and snow reflects 80 percent of the sun’s rays.

SPF is an indication of a sunscreen’s effectiveness in preventing sunburn related to the length of time in the sun, but it does not actually increase proportionately. An SPF of 35 blocks 97-98 percent of the UVB rays, while an SPF of 15 blocks 93 percent of the rays, and an SPF of 2 screens 50 percent of the UVB rays.

SPF only relates to a sunscreen’s ability to block UVB rays. Unfortunately, at the present time there is no measure to quantify the effectiveness of a sunscreen’s ability to block UVA rays. It is well known that chemical sunscreen ingredients that block UVA rays are somewhat unstable when exposed to UV rays and oxygen (air). This is further complicated by the fact that we do not have the ability to measure the stability or effectiveness of chemical sunscreens that block UVA rays.

The most reliable and effective ingredients for protecting the skin from UVA rays are physical sunscreen ingredients. Zinc oxide and titanium dioxide are the two physical blockers used here in the United States. Unlike years ago when physical blockers looked like a white paste on your face, nanotechnology has eliminated this problem by creating micronized particles of zinc oxide and titanium dioxide. Micronized zinc oxide and micronized titanium dioxide are transparent when applied to the skin.

The ideal sunscreen must be broad spectrum; that is, containing agents that can provide protection from both UVB and UVA radiation.

All FDA-approved sunscreen ingredients have a particular absorption spectrum. The ideal sunscreen would combine ingredients to expand the range of ultraviolet protection from damaging ultraviolet rays and should include either micronized zinc oxide or titanium dioxide, given the lack of knowledge regarding the effectiveness of chemical UVA blockers. In addition, it has been shown that daily use of a sunscreen increases its photo-protection, as sunscreen ingredients can bind to skin cells in the outer layer of the skin.

In recognition of the fact that April is Rosacea Awareness Month, it seemed appropriate to talk a little about some of the recent research into the causes of rosacea, which will hopefully, in turn, lead to better treatments and prevention.

Honing in on one specific cause of rosacea may be impossible, however, researchers are now uncovering some promising theories and doing further studies to help solidify what they have found thus far.

The results of some of the research being done points to the following causes:

• Blood vessel disorder
• Genetic predisposition
• Demodex folliculorum (skin mites)
• pH balance
• Cathelicidins

The theory behind the blood vessel disorder is that pimples and/or the tissue growth associated with phymatous rosacea is instigated by the fluid built up in blood vessels, causing them to expand. This fluid can set off inflammation. Structural abnormalities have been noted in the blood vessels of rosacea patients studied.

A lot of attention is being given to the study of Demodex folliculorum…skin mites…as another very viable cause of rosacea. It is a little disconcerting to think about mites living on our skin, but it is a reality that researchers believe makes rosacea a struggle for many. The diet of these mites consists of dead skin cells. The mites make their homes in our hair follicles on our bodies, preferably our faces. When studying the skin samples taken from those suffering from rosacea, researchers recently found the skin mite population of the study group to be much higher than those without rosacea.

As we recently discussed in a blog about acne, when sebaceous glands get clogged with oil and dead skin, inflammation (pimples) can occur. This reaction can also be caused by hair follicles clogged by skin mites. One study conducted by researchers in Ireland found that bacteria carried by the skin mites caused adverse reactions in rosacea patients and not in those who did not suffer with rosacea.

A couple of weeks ago, I talked about “desquamation”, the process by which your body sheds old, dead skin cells naturally. This week I wanted to touch on chemical peels and how they can assist in removing dead skin while also addressing other skin issues.

As your skin ages and suffers years of sun damage, the texture of it can become rough, discolored, and it can begin to lose its firmness. Exfoliation can help, but normal exfoliation is a superficial process restricted to the stratum corneum. Chemical peels accelerate the normal desquamation process and generate a quicker exfoliation of the stratum corneum.

Chemical peels can be superficial, but based on the type of peel, they can also reach to a medium depth, affecting deeper cell layers in the epidermis. Medium-depth peels are used to treat discolored skin, hyperpigmentation, fine lines, wrinkles, sun damage and precancerous skin lesions. Medium-depth peels usually take between 30 and 60 minutes to administer. Side effects include moderate stinging or discomfort for 30-60 minutes.

The depth of peels depends on the active ingredient(s), the concentration of the active ingredient(s), the number of passes or layers applied, the type of skin (thin or thick), the type of skin preparation (eliminating residual sebum and creating an even pH), the application technique, the anatomic location, the application contact time and finally, the spacing of subsequent peels.

The way in which they work is that the chemical peels create a wound in the epidermis, which stimulates cell growth (the healing process) and the formation of important substances deficient in sun damaged and aging skin. But all peels are not created equal and their effectiveness and the depth to which they will go depends on the ingredients in your peel. Superficial peels typically use one or two active ingredients, such as alpha hydroxy acids (glycolic acid) or beta hydroxyl acids (salicylic acid) to remove the epidermis, or uppermost layer of skin. Medium-depth peels penetrate deeper into the epidermis.

Single agent peels lack uniform penetration due to the variability of skin penetration. Peels with multiple ingredients produce a synergistic effect and more uniform sloughing of the stratum corneum, in addition to having a reparative effect on the deeper layers of the skin.

I’m very excited about our (Rx Systems PF) new, soon-to-be-released Poly-Organic Peel. Our Poly-Organic Peel is a novel, cutting-edge new peel designed to repair photo-damage and brighten skin tone. We’ve created this peel by selecting a combination of complementary ingredients with different modes of action to produce a synergistic affect, creating a brightening and lightening peel, while also improving cell growth, exfoliation, and firmness.

Our combination of exfoliative and reparative natural organic acids includes a unique, innovative blend of peeling agents:

• alpha-hydroxy acid (glycolic acid)
• beta-hydroxy acid (salicylic acid)
• dicarboxylic acid (azelaic acid)
• aromatic organic molecule (resorcinol) and
• hydroxyl-pyrone (kojic acid)