10 Aug skin pigmentation and sun exposure? How is this related?
Skin pigmentation related to sun exposure has been researched intensively during the last decade.
Regular exposure to the sunlight evidently contributes to maintain normal levels of vitamin D, crucial hormone responsible for overall health. there are evidences that exposure to sun can prevents many devastating disease, such as cancer, multiple sclerosis, hypertension, diabetes.
The science is showing the effect of sunlight to circadian rhythm also known as body clock, therefore regulating synthesis of melatonin, serotonin and other hormones, that are in particular in control of stabilizing mood.
However, since of the discovery or UV radiation as the environmental causes of skin cancer, the approach has changed and many prevention programs have started to develop and implement.
What is the difference between the waves?
The radiation emittion includes visible, infrared (IR) and ultraviolet (UV) light. Many factors affect radiation, for example snow reflects 90% of UV, while sand reflects 15-30%. Water also strongly reflects UV and sun rays can pass through water in about 1m of depth. The strongest radiation reaches the earth in the summer months, especially between 10am to 5pm.
Ultraviolet radiation (UVR) is one of the most important environmental factors influencing human body. It is invisible to human eye and it is divided in 3 main classes:
- UVA has wavelength range of 320 to 400 nm. It is causing delayed reactions to the skin
- UVB has wavelength range of 280 to 320 nm: it has high energy and potent erythema effect
- UVC has wavelength range of 100 and 280 nm, they are the shortest wavelength, but the highest energy level therefore the most dangerous one. It is absorbed by the ozone layer and does not reach the earth.
UVA represent 95% of total radiation, and it is present all day. It can penetrate through clouds, windows and clothing. It is responsible for photo-toxicity, photo-aging, epidermal thickening and affects immunity of the skin. It penetrates to deeper layers of the skin, affecting collagen fiber and cell synthesis.
UVB represent about 10% of the spectrum that reaches the earth. It is the main cause of sunburn and also place role in photo-aging. It affects skin pigment melanin, directly damages DNA. The reactions caused by UVB are immediate and noticeable as erythema and edema, or sunburns.
This is also a premature aging and refers to the prolonged exposure to sun. These are visible skin changes, manifesting as skin lines, wrinkles, skin pigmentation, loss of skin elasticity and skin dryness. Causes are both UVA and UVB radiation. While UVB radiation is responsible for damage to the lipid barrier and structural skin cells changes, UVA radiation
Is responsible for damage to connective tissue by braking the collagen structure and changes in microcirculation that can be permanent.
Dark spots are also a result of chronic exposure to UV radiation. The mechanism behind skin pigmentation might be the accumulation of abnormal elastin masses. An uneven stimulation of pigment cells as a result show as freckles and age spots that usually look like irregular areas of the skin with range of colors, from light to dark brown.
This condition is common in light skinned individuals with symptoms as scaling lesions with slight erythema typically on face, back of hands, forearms and legs. Onset is usually after 50 years of age and it is more common in males.
This is the most serious UV radiation related skin damage is skin cancer. It happens with the long term, chronic exposure, therefore people with visibly photo-aged skin are at greater risk. It leads to malfunctioning the repair DNA system that is responsible for removing damaged DNA mutations.
The prevention – how to avoid skin pigmentation and skin damage
While there are many ways how to avoid sun damage, we also want to enjoy the sun and all the benefits if gives to our overall health. The question is, where is the balance? What is the sweet spot?
- Avoid direct sun exposure 10am – 5pm (while UVB are the strongest)
- Wear protective clothing preferably darker colors, long sleeves pants, hats, sunglasses
- If you are taking medications, speak with a pharmacist to understand better if this medication may affect your reaction to sun exposure and what actions to take.
The sunscreens and the magic behind SPF factor?
.SPF or sun protect factor in a sunscreen is measuring protection against UVB radiation. It is the ratio of the amount of UV radiation causing erythematous reactions using a filter to the amount of radiation resulting in the same burn without filter protection.
If we want to compare SPF 15 to SPF30, doses of UV radiation that re able to penetrate the skin are two times higher in SPF15 then SPF 30. This is very important when determination the right protection for the skin.
Some of the integral part of SPF sunscreen are physical filters. Physical filters are molecules that are large enough to not penetrate the skin, but still form a barrier to UV radiation on its surface. Some of them are ZnO, TiO2, talc, caolin. The purest one is TiO2. Good thing about physical filters is that they are inert, they don’t absorb or react with skin, and therefore they are safe for use in sensitive skin or even in kids.
Chemical filters represent absorption coefficient. The regulations are clear and create a list of authorized chemicals that are allowed to be used in this indication.
How much is enough – tips:
We advise our patients to use teaspoon rule.
- Face and neck = 1 teaspoon
- Each upper limb= one teaspoon
- Stomach, back and each lower limb = 2 teaspoons
- Don`t omit ears and lips.
What can we do about skin pigmentation?
Many chemical and natural products are used in cosmetics to treat skin pigmentation. While most of the whitening creams are available for free purchase on any shelf, their efficacy is questionable.
In years of our pharmacist practice, we have seen many cases with severe skin pigmentation on a very visible places, and that was disturbing for our patients. They were seeking for solution, for safe and potent topical cream that will resolve the issue. This is the reason we have tight relationship with medical ad naturopathic doctors, where together we are able formulate compounding and to customize the solutions for our clients.
Some of the skin pigmentation treatment products we use in our compounding laboratories:
Vitamin A derivate Tretinoin is usually used in dark spots that appear after skin damage, like severe acne or other lesions. Although the exact mechanism is not known, it is reported that it might the the result of melanin dispersion and redistribution.
The organic acid or Kojic acid is obtained from different types of fungi and sometimes from fermentation from different food. It blocks tyrosinase, the enzyme required in the process of tyrosine transformation to melanin, the skin pigment. In addition, it has other properties as: anti-oxidant, anti-inflammatory and even anti-tumor.
This chemical inhibits melanin synthesis. It should be applied in a thin layer, to entire face to prevent uneven pigmentation. It is also very important to apply sunscreen regularly, while on this treatment. The health professional needs to monitor the result and assessments are necessary to estimate duration of therapy.
Most of the studies evaluating the skin lightening products came to the conclusion that combination with multiple products in different doses achieve the best results. This approach is common in physician practice and tight collaboration with experienced compounding pharmacy is critical for success.
Ascorbic acid or Vitamin C, is very potent anti-aging molecule, due to its anti-oxidative, collagen-producing, and pigment-reducing effects. Humans have to get Vitamin C from food sources, however since its active transport from our digestive system is low, it is hard to achieve optimal skin level of Vitamin C from food alone. Vitamin C level decreases with sunlight and pollution and topical creams with Vitamin C can provide an ideal solution.
Vitamin C protects against oxidative stress by scavenging reactive oxygen species and other free radicals that are a result of normal daily function, UV radiation, and/or pollutants.
Other properties of vitamin C:
- Increases collagen synthesis
- Increases skin elasticity
- Has anti-wrinkle properties
- Affects pigmentation by suppressing the enzyme crucial in formatting the pigment
- Treats erythema
- Protects from sun damage
The pharmacist role in treating these conditions is valuable, whereas starting from a formulation, preparation or compounding or correct dispensing. Moreover, the most important pharmacist role is thorough .patient counseling and follow up.