Tanning and Photosensitivity

Generality

The tan, currently sought after and desired because it is synonymous with beauty, is actually a defensive strategy implemented by the skin, in order to protect itself and the entire body from damage resulting from direct - and, unfortunately, often uncontrolled - exposure to light solar and / or artificial UV rays (tanning lamps).

Skin Defense Mechanisms

The defense mechanisms put in place by the skin to protect itself from UV radiation involve both the melanocytes and the synthesis of the melanin pigment (responsible for the coloring of each individual's skin and its tan), and the keratinocytes present in its most superficial layers.

In fact, ultraviolet radiation increases the number of active melanocytes, thereby stimulating the production of melanin (neomelanogenesis).

This substance (also present in the hair and in some parts of the eye) is synthesized by melanocytes starting from tyrosine, tryptophan and phenylalanine. It is responsible for short and long term tanning. In the first case, generally observed only in people with a moderately dark complexion, there is a photo-oxidation of the melanin that tends to become darker.

This phenomenon occurs immediately after sun exposure and recedes within a few minutes.

Melanin, therefore, if on the one hand it guarantees a darker color (tan), on the other it protects the skin from the negative effects of solar radiation by acting as a real filter. This substance is in fact able to hinder the penetration of ultraviolet rays into the deeper layers of the skin.

The keratinocytes intervene instead in a second protection system: skin thickening. Ultraviolet rays (especially UVB rays) stimulate the proliferation of the cells that form the outermost layer of the skin (stratum corneum).

A greater skin thickness thus prevents ultraviolet rays from penetrating deeply and damaging cells.

photodamage

The defense mechanisms described above are intended to protect the skin from photodamage or damage caused by light (from the Greek photos = light).

In the event of overexposure these mechanisms may be insufficient and the excess of absorbed ultraviolet radiation causes the appearance of more or less serious skin damage.

The main damage caused by the sun and UV rays will be briefly described below.

Sunburn

There is talk of erythema or sunburn when there is a - though minimal - skin redness. Erythema is nothing but the classic sunburn, responsible for symptoms such as heat, boils and general redness.

Depending on the severity of DNA damage, the cell can also undergo premature death. This is why the severe burn is particularly painful and is almost always accompanied by blisters and striking skins (skin exfoliation).

The sunburn is attenuated and gradually regresses within a few days. The extent of erythema, which in turn depends on the phototype and the dose of UV absorbed, is proportional to the healing time.

Typical symptoms of sunburn are itching and pain. To obtain relief and to promote healing it can be useful to apply products with a moisturizing and emollient action. In the case of particularly serious burns, however, it is necessary to seek medical attention.

Skin discoloration

Lack of adequate skin protection during sun exposure can cause unpleasant blemishes such as discoloration or skin spots.

Although in many cases the sun is not directly responsible, it can become responsible in particular circumstances. This is the case, for example, of senile lentigo, which usually appear in late adulthood due to prolonged exposure to solar or artificial ultraviolet rays (tanning lamps).

Treatments to counteract skin blemishes can be different and range from the use of lightening creams to chemical peels, to then move on to real aesthetic treatments, such as, for example, microdermabrasion.

Skin tumors

Skin cancer is the most serious and dangerous damage caused by the sun and UV rays. Among the various neoplasms that can affect the skin following excessive and uncontrolled sun exposure, we mention, for example, squamous carcinoma and basal cell cancer, (often referred to as "non-melanoma skin tumors"). These neoplasms are not fatal as they do not create metastases.

Even moles and warts are examples of benign and non-fatal skin cancers.

Malignant skin melanoma, on the other hand, although less frequent than the previous ones, can be lethal.

Prolonged exposure to the sun, especially for the most photosensitive subjects, increases the risk of developing this type of pathology. In particular it is good to also evaluate the total exposure time during the course of the year and of life (especially during childhood) since, as we have said, the risk of skin cancer increases with increasing time and intensity of exposure.

Proof of this is the fact that skin tumors develop mainly at the level of the parts of the body most exposed to the sun such as the face, ears, neck, arms, shoulders and back.

Of course, the treatment of these serious diseases involves the intervention of the doctor who - depending on the type of cancer that has affected the patient and according to his severity - will be able to indicate the therapeutic strategy that best suits each case (drug therapy with chemotherapeutic drugs anticancer, radiotherapy, surgical treatment, etc.).

In the next article we will see the behavioral rules to follow to minimize the risks of sun exposure and prevent these dangerous pathologies. We will also learn to recognize the symptoms and to understand when it is good to consult a specialist.

Wrinkles

The relationship between wrinkles and UV rays is well known, the main cause of premature aging of the skin (especially of the face), also known as "photo-aging".

Typical of photo-aging are the so-called actinic wrinkles that are characterized by giving the skin a crumpled appearance, otherwise called "parchment".

An excessive tan, in fact, causes the breakdown of collagen and other skin cell structures with consequent structural failure and the appearance of more or less pronounced wrinkles.

Dryness and roughness, dehydration, reduced elasticity and skin sensitivity are other consequences of premature aging of the dermis which must therefore be adequately protected during sun exposure.

The treatment of wrinkles can be carried out through the use of special cosmetics and anti-aging and anti-wrinkle supplements which, however, will not be able to solve the problem definitively and completely.

Alternatively or in association with the aforementioned cosmetics and supplements, one can resort to aesthetic treatments such as chemical peels, or to laser, filler and Botox technologies, or even cosmetic surgery (lifting or mini-lifting anti-wrinkle ).

Eye Effects

The effects of the sun and UV rays on the eyes are perhaps the least known, but they are equally harmful. In fact, ultraviolet radiation can cause significant damage to the cornea, retina and lens with symptoms such as corneal pain, photosensitivity, lacrimation and spasm of the eyelids.

The use of protective glasses should therefore not become a simple option: glasses with dark lenses should always be present in case of prolonged exposure, especially during the hottest hours of the day. Even a wraparound frame is important to prevent radiation from reaching our eyes.

Gradient or clear colored lenses, in many cases are not able to sufficiently protect the eye.

To protect the consumer, manufacturers of sunglasses are required to report on their products the filtering power that can range from 0 (almost no protection) to 4 (maximum protection, useful in extreme conditions, such as at high altitudes).

Finally, it is good to remember that the simple closure of the eyelids is not alone able to protect the eye from the damaging effects of sunlight.