Phototherapy for psoriasis

Psoriasis is a chronic relapsing disease. It is generally believed that it is almost impossible to cure it; at best, the disease is transferred to a persistent period of fading of the process. Experts offer more and more new methods of treating psoriasis, and many of them really help to "forget" for a long time about unpleasant symptoms. Such methods include phototherapy, or light therapy - irradiation of the skin with ultraviolet rays. Phototherapy for psoriasis is used very often, although the irradiation procedure can be applied to other dermatological pathologies.

The effectiveness of phototherapy in psoriasis

The effectiveness of phototherapy in psoriasis depends on how deep the ultraviolet rays penetrate deep into the tissues. At the same time, phototherapy, which combines irradiation with ultraviolet light and the use of long waves, with preliminary ingestion of photosensitizing drugs, is recognized as the most effective.

Phototherapy can provide for the use of different rays:

• narrow-wave UV-B treatment affects the epidermal layer;
• UVA irradiation penetrates deeper into the skin tissues.

The therapeutic effect of ultraviolet irradiation is due to their interference in the processes of synthesis of tissue hormonal substances - the so-called cytokines, which possess the property of immunosuppressors, that is, they suppress immunity. Simultaneously, under the influence of ultraviolet irradiation, there is an update (transformation) of cellular structures, which facilitates the removal of cells from the state of programmed cell death (apoptosis).

Advantages and disadvantages of phototherapy

Phototherapy for psoriasis is a procedure that has a number of undeniable advantages over other similar methods of treating psoriasis:

• treatment is well tolerated by almost all patients;
• The method is safe for medical professionals who directly participate in the procedure;
• results after the end of phototherapy almost always meet expectations;
• with local use of phototherapy, the dosage of irradiation can be clearly controlled, thus minimizing the degree of carcinogenic risk and total irradiation;
• With the general use of phototherapy, it is possible to prevent the appearance of psoriasis in healthy areas of the skin.

But, as with any other method, with phototherapy sometimes there are side effects that you should know about in advance. Such manifestations can occur immediately after the procedure, or declare themselves, months and even years later.

Among the early manifestations can be identified as follows:

• excessive dryness of the surface layers of the skin;
• sensation of itching;
• sites of hyperemia in the form of light-toxicity erythema.

Late adverse symptoms are found much later and can be manifested as:

• photoaging of the skin;
• hyperpigmentation, spots on the skin;
• atypical skin degeneration (malignancy).

[1], [2]

Indications for the procedure

Phototherapy for psoriasis is prescribed mainly in order to establish a stable period of remission in the exudative and simple (classical) course of the disease - for example, with psoriasis of the head, palmar and plantar surfaces.

It is possible to use this method for therapy in the presence of pustules and erythroderma, especially in difficult cases. For the treatment of such patients, apparatuses are used that are usually intended for local exposure.

As a photosensitizing substance, tablets are taken: Ammifurin or Metoxalen.

Selective phototherapy is prescribed to eliminate the symptoms of the classical and exudative psoriatic process - both with moderate manifestations of the disease, and in the stage of increasing symptoms.

[3], [4]

Technique of the phototherapy for psoriasis

At the moment, medicine uses three methods of phototherapy close to each other in the course of psoriasis:

1. photochemotherapeutic method, which is a combination of UFO with oral intake of photosensitizing agents;
2. selective phototherapy, combining the use of long and medium waves;
3. narrow-band phototherapy, which is carried out using UVB-irradiation with a maximum emission of narrow-wave beams of 311 nm.

• Photochemotherapy is considered the most effective, since a positive outcome after treatment is observed in 88% of cases. Treatment involves carrying out from 3 to 4 sessions per week, with the total duration of the course - to complete cleansing of the skin from psoriatic plaques. Usually it can take from 15 to 25 procedures. The initial dosage of irradiation can vary in the range of 0.5-1 J / cm². Each second session is carried out with an increase in the dosage of exposure by 0.5-1 J / cm². If the skin is cleaned slowly, the doctor may decide to use local irradiation.
• Selective phototherapy for psoriasis is considered effective at about 85%. Conducted for 5 sessions per week with an initial dosage of 0.05-0.1 J per cm². The total duration of therapy is approximately 25 procedures.

It is characteristic that selective phototherapy for psoriasis of the head implies the use of a special UV-crest, which allows to exert even through a hairy barrier. Such a comb can be used not only on the head, but also on the legs, chest, in the groin and underarms.

• Narrow band phototherapy for psoriasis is close to photochemotherapy in efficiency. This method rarely causes complications such as burns, flushing, malignant degeneration of the skin.

For the therapy, specific lamps are used, which are exclusively manufactured by Philips. Lamps contain a special gas and consist of glass, which is capable of transmitting only lightwaves of a certain length.

This procedure can be carried out locally and segmentally. The sessions are repeated 3 to 5 times a week at a starting dosage of 0.1 J / cm2. If the response to treatment is good, then each subsequent session occurs with an increase in dosage by 0.1 or 0.2 J per cm². The total number of procedures is about 25.

Contraindications to the procedure

Unconditional contraindications, in which categorically impossible to conduct phototherapy for psoriasis, a little. They include the following cases:

• The presence of tuberculosis (phototherapy can dramatically worsen the course of tuberculosis, due to a sharp stimulation of metabolic processes).
• Diseases of the organs of vision (phototoxicity is possible during the procedure).
• Diseases of the skin, accompanied by photosensitivity.
• Manic or hypomanic conditions that are present at the time, or occurred earlier.
• Background treatment of drugs that affect the photosensitivity of the skin.
• Porphyrin disease (porphyria).

The use of phototherapy for psoriasis is possible under the strict supervision of a physician with thyroid hyperfunction, as well as during treatment with Methotrexate or Chloroquine.

Among the additional contraindications to the use of phototherapy can be identified:

• malignant neoplasms;
• acute or chronic course of insufficient kidney function;
• severe liver diseases;
• hypertension with a tendency to hypertensive crises;
• insufficiency of cardiac activity;
• diabetes;
• atherosclerotic changes in vessels of severe severity;
• stroke;
• increased possibility of hemorrhages, impaired blood coagulation;
• increased hair growth (hirsutism);
• dermatitis;
• systemic lupus erythematosus;
• acute period of malaria;
• hereditary or congenital hypertrophied photosensitivity of the skin;
• light-dermatoses;
• collagenoses;
• excessive exhaustion of the body;
• cataract;
• disorders of the psyche, proceeding against the background of increased nervous excitability.

[5]

Consequences after the procedure

As we described above, phototherapy for psoriasis can be accompanied by a number of side effects - early and late.

Early manifestations are itching, dryness and redness of the skin in the areas of exposure.

The late symptoms can be actinic lesions and hyperpigmentation of the skin.

Photochemotherapy using photosensitizing drugs - psoralens - increases the risk of eye lens damage. Photosensitizing substances get inside it and under the influence of UFOs create photoadditive metabolites with protein amino acids. Such metabolites are very tightly bound compounds that accumulate inside the lens during repeated sessions of photochemotherapy, provoking the development of pathological changes. To avoid such negative consequences, it is recommended to use specially designed preventive glasses during the procedure, as well as within 24 hours after it.

[6], [7], [8], [9]

Reviews about phototherapy for psoriasis

Phototherapy is a relatively new method in the treatment of psoriasis. Many patients note that already the first few procedures can significantly slow down the growth of skin layers in the affected areas.

During irradiation, ultraviolet rays of various spectra are usually used: B and A.

When irradiated with ultraviolet B, the session continues until the skin becomes pinkish (up to about a minute). Gradually the procedure time increases. When using these types of rays in the form of narrow-band irradiation, the risk of side effects is much lower than when using other types of phototherapy. As experts note, this is due to the fact that only rays of the length necessary for the treatment of psoriasis are used for the effect, and no more.

The ultraviolet of spectrum A penetrates much deeper, and the session lasts longer. The frequency of adverse events in this case is significantly increased.

However, the greatest number of side effects observed after the application of photochemotherapy, although this method is recognized as more effective.

Given all the facts, patients are increasingly choosing narrow-band phototherapy for the treatment of psoriasis. Only this type of treatment can "boast" both the quality of treatment and the minimal set of side symptoms.

According to patients' feedback, in order to completely clean the skin of psoriatic plaques, it is necessary to undergo approximately 20 procedures of phototherapy. After this, twice a year, it is required to visit his attending doctor to observe and eliminate the negative consequences of exposure.

Phototherapy for psoriasis has many positive and undesirable moments. However, it should be borne in mind that at present this method is one of the most effective and effective for getting rid of an unpleasant disease.