What is UV radiation and why is it dangerous?
Ultraviolet radiation is a form of non-ionizing radiation, part of the electromagnetic spectrum with a wavelength of 100 to 400 nanometers (nm).
It is classified into 3 subtypes: UVA, UVB, and UVC. Its main natural source is the sun. All UVC and most UVB are absorbed by the ozone layer. Thus almost all the ultraviolet radiation that reaches the earth consists of UVA rays, which penetrate deeper into the skin up to its basic layer, where the melanocytes are found.1
Artificial sources are the tanning beds (solarium), mercury lamps, mercury and mercury some laser devices. The degree of exposure to ultraviolet radiation varies depending on the day, the season, the latitude or the altitude, while it is related to the profession such as working in the countryside, and lifestyle such as sunbathing, water sports and artificial tanning. .2.3
Ultraviolet rays are reflected in sand, water, snow and ice and penetrate clouds or windows (UVA). Both UVA and UVB radiation affect health. Of course, its effect on the production of vitamin D is positive. Overexposure to ultraviolet radiation is potentially dangerous for the body, as it stimulates melanin-producing cells and the appearance of "tanning", a sign of skin and DNA damage, while more intense Exposure to UVB and UVA leads to burns, indication of more cell death.4
Long-term exposure to UVA leads to photoaging (wrinkles, pigmentation, thinning and atrophy), precancerous lesions (such as radial hyperkeratosis), noncancerous , squamous cell carcinoma) and melanoma.5,6 In addition, it is associated with an exacerbation of photosensitivity skin diseases such as lupus erythematosus and late skin porphyria and ocular lesions such as cataracts and tumors. Ways of protection from ultraviolet radiation Since in our country exposure to ultraviolet radiation is year-round, our protection from it must become a way of life. Protective measures should be taken daily, even on cloudy or rainy days.
The following are suggested:
What is Actinic hyperkeratosis?
Chronic and cumulative exposure to ultraviolet radiation leads to the formation of actinic hyperkeratosis, which is a common skin lesion in people over the age of 50 and is located on the exposed parts of the body, mainly on the face, scalp, neck, chest, back, arms and tibias.10
Although they come in many forms, they are usually presented as variously sized palpable hard patches on the surface of the skin with scales, sometimes accompanied by pain, burning or itching. In other cases they manifest as hypertrophy or skin atrophy, hyperpigmentation, cheilitis or look like a small animal horn, while sometimes the lesions are not visible to the naked eye.11
They occur more often in middle-aged and immunosuppressed men, with light skin color and eyes, with red or blond hair (Phototypes I and II according to Fitzpatrick), in geographical areas with high sun exposure.12 Genetic disorders, a history of sunburn in childhood, and a high-fat diet are also risk factors. Natural factors such as ozone depletion, and increased activities such as sunbathing, tanning, and outdoor work have greatly increased the global incidence of the disease in recent years. They are considered precancerous lesions, since in a percentage from 0.1% to 20% they develop into squamous cell carcinoma.13
Although early diagnosis and treatment of the disease is of great importance for public health, it often does not receive the necessary attention from patients due to lack of information, as well as from doctors of other specialties due to lack of information and untimely referral to a dermatologist.
How to prevent actinic hyperkeratosis
Prevention of actinic hyperkeratosis can be achieved to a significant degree by properly informing the public about the nature of the disease and the negative effects of chronic exposure to ultraviolet radiation, but also self-examination for any changes in the skin with timely referral for medical examination. Regular dermatological examination and absolute consistency in sun protection measures is recommended. New medical devices that combine a high photoprotection index (SPF 50 +) with DNA repair enzymes are proposed instead of the standard sunscreen, for daily use by people with extensive sun damage at high risk of developing precancerous lesions and skin cancer.14
Treatment of actinic hyperkeratosis
Actinic hyperkeratosis must be treated, as clinically we can not determine which lesion will develop into squamous cell carcinoma, with possible metastasis and death.15
The approaches available today are divided into 2 categories. The first includes treatments that individually target each lesion, such as liquid nitrogen cryotherapy, scraping or surgical removal, diathermy and sublimation with laser carbon dioxide or Erbium YAG.
The second concerns field treatments, targeting multiple lesions per area at the same time, such as the use of chemicals (fluorouracil, imicimod, diclofenac with hyaluronic acid, retinoids, ingenol mebutate), chemical exfoliation with trichloroacetic acid. use of newer therapeutic agents, such as resiquimod, betulinic acid, piroxicam, and dobesilate.18
As they all have advantages and disadvantages, the choice of the appropriate treatment is made by the treating physician based on the nature, location and number of lesions, as well as the general condition of the patient. The above options can be combined with the best clinical outcome, with a reduction in the duration and side effects of treatment. In any case, due to the chronicity of the disease and the continuous appearance of new lesions, it is necessary for the patient to comply with the treatment and medical instructions for sun protection, and long-term follow-up by a dermatologist.
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