Psoriasis ultraviolet light therapy

Type:Uv phototherapy   Time:2019-02-12 21:40:53 Psoriasis is a common disease in dermatology, a frequently-occurring disease. The patient presented with recurrent red patches of skin covered with silvery white scalys. The area can range from the tip size to the large piece to the general body. Because psoriasis is a chronic disease, it is easy to recurrent and there is no way to cure it. Patients are often very distressed. The treatment of psoriasis has also become an important topic in ancient and modern skin science. People have done a lot of exploration and research in this area, and many effective treatment methods have been summarized in modern times. The most commonly used are a variety of external preparations, such as hormonal drugs, retinoids, vitamin D derivatives, as well as tar, Enlin, keratin promoter and emollients. Oral medications, including immunosuppressants, retinoic acid, etc., can also be used in more severe cases. In addition to medical treatment, there are some physical means to effectively treat psoriasis, including phototherapy, hydrotherapy, and climate therapy. This article focuses on the most effective and currently the most widely used UV light therapy.

People have long discovered in life practice that sun exposure can improve health and cure diseases. Among the sun's ingredients, the main therapeutic effect is ultraviolet light. The Danish doctor Finson was the first medical scientist to use artificial ultraviolet light therapy to treat skin diseases. He received the Nobel Prize in Medicine and Physiology in 1903 for his pioneering contributions in the application of phototherapy for skin diseases. In 1925, the German doctor Gokman summed up the famous Geckman triple therapy, began to apply the ultraviolet light therapy to the treatment of psoriasis, and widely promoted, and achieved good therapeutic results.

With the advancement of science and technology, the emergence of new artificial light sources and the continuous exploration of psoriasis treatment methods, the method of phototherapy for psoriasis has also developed rapidly. To date, widely used phototherapy is mainly photochemotherapy (PUVA therapy) and narrow-spectrum UV-wave therapy (narrow-spectrum UVB therapy or 311 nm UVB therapy).

PUVA therapy has been widely used in the treatment of psoriasis in Europe and the United States since the 1970s. The specific method is: after oral or topical psoralen drugs (photosensitizers), the appropriate dose of long-wave ultraviolet radiation to the whole body or the patient's part. Both the dose and the dose of light should be determined according to the patient's condition and gradually increase the dose of light. It usually takes 2 to 4 times a week to treat. Most patients are treated for 1 to 2 months, and the condition can be significantly improved or even completely removed.

The mechanism of PUVA therapy is to affect the replication of epidermal cell DNA and inhibit the excessive proliferation of skin cells in psoriasis by the action of photosensitizer and long-wave ultraviolet rays, thereby playing a therapeutic role. Because of the use of photosensitizers in PUVA therapy, patients should be protected from light during the day after treatment. Patients with oral photosensitizers also need to wear special UV-protective glasses to avoid damage to the skin and eyes caused by sunlight. Photosensitizers may affect fetal development, so PUVA therapy cannot be used in pregnant women. Children should be used with caution.

Ultraviolet light (UVB) can treat psoriasis by irradiation alone because it has higher energy than long-wave ultraviolet light. Scientists have found through comparison that the best UV-ray treatment for psoriasis is near the 311 nm wavelength. Therefore, in 1988, Philips produced a narrow-spectrum UVB fluorescent tube with an emission wavelength of 311 nm, which became the best therapeutic light source. Since the development of narrow-spectrum UVB phototherapy, it has become a new and effective treatment method for psoriasis. The specific treatment method is: according to the patient's condition, select a certain initial irradiation dose, ultraviolet radiation to the patient's part or whole body, 2 to 4 times per week, gradually increase the irradiation dose during the treatment, generally after 5 to 10 treatments. The disease can be improved. After 1 to 2 months of treatment, most patients can be basically cured, and even the skin lesions are completely removed. There is mild pigmentation in the affected area after treatment, but it can resolve in a short period of time.

The mechanism of narrow-spectrum UVB treatment of psoriasis mainly has the following two aspects: 1. UVB irradiation inhibits lymphocyte proliferation, reduces the number of inflammatory cells, and reduces the inflammatory reaction in psoriasis. 2. Inhibiting T helper cell-mediated immune responses to treat psoriasis associated with the response.

Evaluation by scientific contrast experiments found that narrow-spectrum UVB treatment is roughly equivalent to PUVA therapy in terms of efficacy. However, the narrow-spectrum UVB therapy has the following advantages over the latter: 1. It is not necessary to take the drug before the light, and the treatment is quick and convenient, and the treatment time is short. 2, do not need to take photosensitizers, no related systemic adverse reactions such as nausea and vomiting, and avoid the limitations of photosensitizers on the indications, the safety of treatment for pregnant women and children increased. 3. No strict anti-light and eye protection is required after treatment. Because of these advantages, narrow-spectrum UVB treatment has been more and more widely carried out in recent years, and there is even a tendency to gradually replace PUAV therapy.

In general, UV phototherapy has the following advantages in treating psoriasis:

1. The curative effect is exact and the efficiency is high. The application of phototherapy in the world has been used for the treatment of psoriasis for decades. A large number of clinical data indicate that PUVA and narrow-spectrum UVB have a very positive effect. Most patients with psoriasis can be treated with appropriate phototherapy. Satisfactory efficacy.

2, the relevant equipment is perfect, can adapt to a variety of sick conditions. Due to the development of technology, we have a variety of artificial ultraviolet light sources, a variety of different specifications of ultraviolet light therapy equipment. Various types of irradiation equipment can be selected for different patients and different diseased parts, and from local patients to systemic diseases and even individual parts, the corresponding equipment can be used for treatment.

3, treatment is quick and convenient, no hospitalization. Phototherapy is usually carried out in the daytime treatment center of the hospital dermatology department. Patients can flexibly arrange treatment time according to their own situation and doctor's advice, only a few minutes to tens of minutes each time. Therefore, it has less impact on normal life work.

4, good safety, no rebound after stopping treatment. As phototherapy methods take longer and more experience, their safety is being widely confirmed. The dermatology community now recognizes that phototherapy is a safer treatment (see below for side effects on phototherapy). Most patients get a longer remission period after treatment. Patients can choose appropriate maintenance treatment after treatment to reduce and delay recurrence.

5, the cost of treatment is not high. At present, the core components of phototherapy equipment cannot be produced in China, so the price of phototherapy related equipment is still relatively expensive. However, the consumption of equipment components is less in the treatment process, so the cost of phototherapy treatment is not very high, considering the high efficiency of treatment, compared with other therapies, the author believes that phototherapy is a more economical treatment.

Due to the above characteristics of UV phototherapy, we recommend many patients to receive phototherapy. However, phototherapy methods for the treatment of psoriasis still have some problems and cannot be ignored:

1. The pathogenesis of psoriasis is still not known by science. The mechanism of phototherapy for psoriasis needs further research. Phototherapy can not solve the recurrence of psoriasis at all, so it is necessary to correctly understand and evaluate phototherapy. The efficacy of psoriasis, in the clinical attention to grasp the indications, to determine a reasonable therapeutic purpose, must be properly applied.

2, phototherapy methods generally have related side effects, including acute erythema, sunburn reaction; medium and long-term treatment will appear dry skin, tanning, sunburn and photoaging skin; long-term cumulative exposure will increase the incidence of skin tumors risk. For individual patients, consider whether there are related phototherapy relative contraindications and absolute contraindications. For example, pregnant women are contraindicated with PUVA therapy. Patients with pigmented dry skin disease are contraindicated with various light therapies. Patients taking certain light-sensitive drugs, skin tumor patients, and children may be relative contraindications for certain phototherapy. All of the above risks require that the phototherapy must be guided by a specialized dermatologist, based on the actual situation of the patient, to grasp the indications and study the combined treatment plan. Avoid acute adverse reactions, reduce cumulative doses and reduce long-term adverse reactions while ensuring appropriate efficacy.

3, the current phototherapy treatment of psoriasis, mainly relying on the summary of clinical experience, has not yet developed a strict treatment norms. The evaluation of efficacy and long-term safety of phototherapy is still underway. This requires doctors and patients to try to understand the relevant knowledge and carefully operate. Can not be carried out blindly and indiscriminately.

4. Psoriasis is a chronic skin disease that is affected by many factors and requires comprehensive treatment. Therefore, in the application of phototherapy, it should also be reasonable to cooperate with other effective treatments and adjuvant treatments. This can improve the efficacy, reduce the adverse reactions of phototherapy, reduce the suffering of patients and improve the quality of life.

Various treatment methods, including ultraviolet light therapy, have been developed through scientific research methods. Such research is still in progress today in the rapid development of medical technology. It is believed that through the development of new methods and the rational use of existing means, the level of medical service protection will be improved, and psoriasis, a disease that has long plagued patients and the dermatology community, can be well resolved.