The sunburn is that inflammation of the skin that we all, more or less, risk as soon as summer comes. At the first heat or ray of sunshine, we try to forget the winter by hiding his labors behind an intense tan. There is no doubt that the “tan” makes us look more beautiful, healthy and serene … but at what price? How can we benefit from the sun without risking sunburn?
Solar erythema: What is it?
The solar erythema is an inflammatory manifestation of the skin due to an excessive and prolonged exposure to UV rays, in the absence of sun protection or in the presence of inadequate sun protection with respect to one’s phototype. Erythema occurs a few hours after exposure and its severity is variable: it can be mild but can become like a first or second-degree burn.
Even the parts of the body do not all react in the same way: the eyes, the nose, the lips are more sensitive than arms and legs.
The structure of the skin
To understand how the skin reacts in the case of erythema we see briefly how the skin is formed.
The skin is composed of 3 parts …
- The epidermis, which represents its most superficial layer, consists of epithelial cells called keratinocytes. The epidermis is divided into layers that depend on the state of keratinocyte maturation. The basal layer is adjacent to the dermis: it is a single layer of cylindrical keratinocytes and represents the germinate layer on which the continuous renewal of the epidermis depends. Among the keratinocytes of the basal layer, we find the melanocytes, which produce melanin. Once secreted, melanin is transferred to keratinocytes.
- Above the basal cells, we find the spinous layer, which normally has a thickness of about 5 rows of cells. Above the spiny cells, proceeding with the keratinization of the cells, we find the granular layer, consisting of 1 or 2 rows of cells. The superficial layer of the epidermis is the stratum corneum, usually of a thickness equivalent to 3-4 cells. These are nucleus-free cells, loaded with keratin filaments.
- The dermis is located below the epidermis and is composed of two parts, the papillary, located in contact with the epidermis, and the reticular , located between papillary and hypodermis. The dermis contains collagen, elastic fibers and glycosaminoglycans, which give the dermis its characteristics of tensile strength, extensibility, hydration and turgidity. In the dermis, we also find the cutaneous appendages, or rather hair follicles and sebaceous glands.
Solar erythema: The causes
Sunburn is an acute damage to the skin. Following this damage there is vasodilation and the release of substances such as …
- Some cytokines
- Nitric oxide
All these substances trigger an inflammatory process appreciable to the naked eye with redness of the skin. But the damage is not limited here: the solar erythema is essentially due to the UVB rays which, due to their high energy level, induce a direct damage to the DNA of the basal cells of the epidermis. Furthermore, continuing the solar exposure, also the UVAs interact with specific cutaneous molecules, inducing oxidation reactions, which in turn create a further cellular damage.
As we mentioned at the beginning, solar erythema is due to excessive or prolonged sun exposure in the absence of sun protection or with a sun protection not adequate to one’s complexion. Each person reacts differently to ultraviolet radiation. The phototype allows us to have a correct exposure to the sun based on our characteristics and the response we have to sunlight.
The phototype of a person is a classification used in dermatology, determined on the basis of the quality and quantity of melanin present in basal conditions in the skin.
Subjects with fair skin, blond or red hair and light eyes are certainly more at risk. The risk of erythema is not only related to the phototype but also to the amount of UV rays absorbed. An important element is the time of day when you are exposed to the sun: between 10 and 16, the sun is more dangerous, especially where there are surfaces reflecting light, such as snow, water and sand.
Furthermore, children under three years of age must be considered at risk. Under the year of life they should never be exposed directly. Above the year, you can expose before 11 and after 17 and always adequately protected with cap, glasses and high protection filter specific for pediatric age. Even the elderly are more vulnerable to the sun.
Symptoms of sunburn
The mild form of sunburn is manifested by a redness that disappears spontaneously after a few days. Scalded skin appears red, hot and prone to itching due to increased blood supply to the more superficial skin layer. Burning sensation and dry skin may occur.
In the most important forms, when the erythema is intense, it appears as a first-degree burn with redness, swelling (edema), vesicles, burning, hypersensitivity to the touch and itching. In this case, after a few days the skin peels off. If the erythema is very extensive and intense it may be accompanied by fever, chills, nausea, headache and dizziness.
The dangers of erythema
We have mentioned it before: solar erythema is only the visible part of the acute damage induced by UV rays.
UV rays induce mutagenic cell damage. The skin has mechanisms to repair damage to the DNA: the P53 protein that blocks the replication of damaged cells or, if the damage is large, induces apoptosis, or programmed death. Repeated damage over time leads to chronic damage that is evident with photo aging, immunosuppression and photocarcinogenesis.
Unregulated sun exposure is an important risk factor for the development of skin tumors such as melanoma, basal cell carcinoma and spinocellular carcinoma. In particular, epidemiological studies have shown a correlation between acute and intermittent sun exposure and risk of melanoma, while so-called non-melanoma skin tumors are mostly associated with chronic and continuous exposures.
Over the years, the burns predispose to the appearance of skin spots and can cause premature aging of the skin: this means that it loses its natural elasticity causing the appearance of wrinkles.
How to cure erythema
In the case of mild erythema, it will be sufficient to apply moisturizing and soothing products based on arnica, aloe and chamomile. Cold running water and ice bags can help counter the burning. On the other hand, solar erythemas with blisters and bubbles require more attention. In this case it will be advisable to consult the dermatologist who can indicate medications with antibiotic and cortisone creams. To relieve itching and burning it may be necessary to use NSAIDs and antihistamines by mouth.
Natural remedies against erythema
If solar erythema appears it is important:
- Drink plenty of water to rehydrate your skin
- Use cold packs on the irritated area
- Immerse the part affected by erythema in fresh water to relieve the sense of heat and itching
- Apply moisturizers with natural substances such as aloe vera, starch and chamomile.
What should not be done?
It is important to avoid DIY in case of intense erythema with blisters or blisters: in this case, it is necessary to consult your doctor or dermatologist. After that, you should not go back to the sun until the sunburn resolves.
How to prevent sunburn
To avoid the appearance of a sunburn it is advisable to act with adequate prevention …
- Wear fresh clothing that covers the skin and protects it from direct exposure to sunlight;
- Use sunscreen with a high protective factor or in any case suitable for your skin type;
- Avoid exposure to the sun during the hottest hours, i.e. between 11 and 16, when the concentration of ultraviolet rays is higher;
- Accustom the skin to the sun gradually, starting with short exposure periods that will become progressively longer;
- Choose in advance a diet rich in substances that prepare the skin, such as beta-carotene, vitamin A, vitamin E, vitamin C and antioxidants.