A recommendation must be clear: the doctor must not be omitted! Any treatment must be carried out under the supervision of a competent doctor, whom you can turn to BEFORE, DURING and possibly AFTER the phototherapy treatment.
UV rays make up about 8% of the total solar radiation, 75% of which is UVA, 19% UVB and 6% UV-C.
UVA rays (330-400 nm) are responsible for tanning and photosensitive reactions. They penetrate deep into the skin, causing premature aging.
UVB rays (280-330 nm) affect the immune system, calcium metabolism and bioavailability of vitamin D; they may cause sunburn and are used for therapeutic purposes. Inadequate exposures increase the risk of skin cancer.
UV-C rays (200-280 nm), the most dangerous, are absorbed by the ozone layer; they are used for technical purposes, for sterilization.
The beneficial action of sun exposure has been known for a long time, especially in the summer when one goes to the seaside: the psoriatic spots improve considerably, sometimes seeming to disappear completely, but unfortunately the remission is transitory, spots are bound to reappear shortly after the end of the holidays. For vitiligo, the phenomenon is similar, but the depigmented areas are much more sensitive to the risk of sunburn, so many people tend to stay out of the sun, to also avoid the inevitable discoloration (map-like skin).
Furthermore, the ability of the sun to enable a “coin repigmentation” is well assessed, by stimulating the inactive melanocytes that, in the affected areas, do not allow for a more uniform coloration anymore.
Once these beneficial effects were associated with sea water, but in the meantime it has been established that the reasons lie in exposure to the sun and, more precisely, to the frequencies of the ultraviolet rays of type B. The most important photo-biological effects induced by UVB are:
- the modulation of the immune system
- the synthesis of vitamin D and the metabolism of calcium
- the regulation of cell proliferation
- the stimulus to produce melanin
Balneotherapy and light therapy are the most natural forms of phototherapy, unfortunately not usable on all latitudes, all year round and especially at the pace which we are led to live, so it may be useful to take advantage of the benefits of UVB by getting it from artificial sources as well, with doses that are strictly measured and adapted to suit each specific case.
In the last twenty years, many centers equipped with UVA light sources for tanning purposes emerged; their success has been due to the common culture that associates a tanned complexion with health and beauty. Many people, ignorant or unaware of the risks they face, are undergoing significant and prolonged doses of UVA, for the sole purpose of appearing tanned; they do not take into account the rapid aging which their skin is undergoing (also known as photo-aging).
In the 70s, dermatologists discovered the use of ultraviolet rays in the treatment of psoriasis and, more recently, of vitiligo: with PUVA therapy, patients are subjected to UVA emissions after taking photoactivable drugs (psoralen). Effective, but with side effects that are not indifferent, furthermore unadvisable for long term use, due to the always present risks of high liver toxicity and damage to the eyes.
Since then, the study of UV rays has made great advances: the use of UVB has given great benefit to the treatment of psoriasis. The study of Parrish & Jenicke of 1981 opened a new road, stating that the frequency with the most therapeutic response is between 311 and 313 nanometers, in full UVB field.
Modern technologies have allowed the build of fluorescent tubes that produce restricted emissions (narrowband) compared to those that offer the entire range of UVB (broadband) and which are already extremely effective against psoriasis. Today, with narrowband UVB, amazing results are obtained even in the repigmentation of skin affected by vitiligo, by using selective phototherapy (SPT).
Widely used in both hospital environments as well as in home care, being high-efficacy therapeutic equipment suitable for long-term treatments, suitable for treating psoriasis and vitiligo as emitters of ultraviolet rays of type B, are:
- Broadband, tried and tested for decades, but which are strongly erythematous
- Narrowband, extremely selective and more effective, have superseded all others
The use of UVA rays is to be avoided, since they are poorly effective at therapeutic level and mostly unnecessary, except in certain cases of acne, atopic dermatitis or psoriatic arthritis. Regular and constant care, following the treatment protocol that the dermatologist has established for your personal conditions, is the essential condition for obtaining excellent results without any risk.
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