PUVA-therapy psoriasis

The beneficial effect of sunlight on many skin diseases has been known since ancient times. However, in the matter of skin irradiation with naturally occurring UV radiation, the most important aspect has always been the need to strictly dose the radiation received. Thanks to the invention of artificial sources of ultraviolet rays – special lamps with a specific radiation range, the use of UV radiation in medicine has taken a significant step forward. For example, one of the modern achievements of physiotherapy is the PUVA therapy technique, which is used, among other things, for the treatment of psoriasis. PUVA therapy is based on a combination of exposure to the skin of ultraviolet rays and special chemicals.

Psoriasis: what kind of disease and why is it dangerous

Psoriasis is a non-infectious lesion of the skin. The main symptom that characterizes it is specific psoriatic plaques, which gradually replace the healthy skin area. This disease affects women and men, children, adults, the elderly, and the geography of its prevalence covers almost the entire planet. It is called the disease of the young due to the fact that approximately 70% of all cases of the disease occur in people aged 15 to 25 years.

The affected person pays attention to the appearance of itchy and flaky skin areas, which, as it were, rise above healthy skin – psoriatic plaques. These plaques, in themselves a pronounced red color, are covered with a white coating, similar to a thin layer of wax, and may have whitish scales.

Formations can cover the skin throughout the body, but are most often found in places of fold and friction of the skin: on the buttocks, knees, feet, in the elbow and knee folds. In addition, the lesion is often localized in the scalp, near the ears, on the hands and around the nails, in the vulva.

The area of ​​the plaque can be insignificant – the size of a match head, or spread over the entire surface of a part of the body. Lesions are rarely solitary, and if a psoriatic plaque is found anywhere on the body, most likely it did not appear alone. In addition to the characteristic appearance, the development of the plaque is accompanied by severe itching and flaking. When combing, scales are separated from its surface. Sometimes a crack or suppuration may appear at the site of the lesion, for example, as a result of mechanical combing. Violation of the integrity of the skin at the site of the plaque is accompanied by pain.

Physicians consider the Koebner phenomenon to be a separate type of psoriasis, in which skin lesions provoke its mechanical damage, for example, ordinary scratches. The syndrome is also characterized by a significant deterioration in the condition of the nails.

The most common are two forms of psoriasis:

• summer, when the disease manifests itself due to sunlight, and exacerbations occur precisely in the summer season;
• winter, when the skin reacts to a sharp cold with the development of a psoriatic lesion.

One of the dangers of psoriasis is that the causes of its appearance are still not known to medicine. Among the possible factors provoking the development of the disease are:

• genetic reasons;
• autoimmune disorders;
• neurological pathology;
• metabolic disorders.

In fact, psoriasis does not cause any significant danger to the health or life of the affected person, however, it creates a lot of problems for a person, ranging from unpleasant and painful sensations to serious psychological complexes and problems in communication with the outside world.

What is the essence of PUVA therapy

The PUVA treatment method is the use of a special photoactive substance that is applied externally or taken internally. In parallel, controlled irradiation of the skin with long-wave ultraviolet radiation occurs. In addition to difficult cases of psoriasis, PUVA is prescribed to combat such diseases:

• atopic dermatitis;
• fungal mycosis;
• vitiligo.

The scientific study of the properties of ultraviolet radiation for human skin was first carried out at the end of the 19th century by the Dane Niels Finsen. Using carbon arc lamps, this scientist pioneered the use of ultraviolet radiation to treat lupus erythematosus. In 1896, the Finzen Institute for Light Therapy was founded in Copenhagen. During the first five years of its existence, about 800 people were treated there, 400 of whom got rid of their ailments.

In 1902, the French engineer Gustave Pierre Trouvé began designing a portable apparatus for concentrated ultraviolet radiation for the treatment of skin diseases. Over the next 70 years, treatment with UV rays was, in some way, experimental in nature, and only in 1974 was the first source of intense UV radiation developed, which gave doctors the ability to control the dose of radiation, thereby relieving patients from the negative effects of therapy.

Further, this method of dealing with skin ailments gradually began to be introduced everywhere. Since 1978, it has been actively used, first in the United States and then in Europe, for the treatment of psoriasis and other skin lesions. Statistical data of the world medical community indicate the success of the method in about 80-85% of cases.

Separately, both UV radiation and photosensitizers do not have a significant effect on the skin. Once in the skin cells, the photoactive drug psoralen is activated only when it is exposed to ultraviolet rays of a certain length. In such an active state, they interact with the DNA of epidermal cells, resulting in selective inhibition of DNA synthesis in epidermal cells, but the functions of the cells are not suppressed.

An hour and a half after taking a photoactive drug, photochemical DNA binding occurs due to the absorbed protons of UV radiation. Cyclic bonds are established between the pyrimidine bases of cellular DNA and the photosensitizer.

The general scheme of action of the photosensitizer looks like a process of creating cross-links of the “DNA-psoralen” type, which reduce the synthesis of DNA in epidermal cells, that is, they directly affect the causes of the appearance of psoriatic plaques.

Provoking the metabolism of arachidonic acid occurs due to the formation of reactive oxygen species that damage the membranes of epidermal cells. Psoralen molecules also catalyze chemical reactions that inhibit pathological keratinization and provoke the death of lymphocytes and keratocytes.

Thus, the combination of ultraviolet radiation and photosensitizing substances significantly enhances the effectiveness of ultraviolet radiation in combating skin diseases, including psoriasis.

Technique for the implementation of PUVA therapy

Carrying out procedures of this nature became possible only thanks to the invention of devices that produce directional UV radiation of a certain length. Special booths or screens have built-in fluorescent lamps, which are the source of UV waves in the range from 320 to 400 nm. The effectiveness of the procedure can be maximum at the wavelength range of 350-365 nm.

PUVA devices are available in various modifications – the patient can stand or lie down during the process, or receive a dose of exposure only to a specific part of the body, for example, the head, feet, knees or elbows.

Whole-body irradiators are generally installed only in appropriate medical facilities, while portable devices designed for local exposure can be used even at home.

Varieties of PUVA therapy used to combat psoriasis

Doctors differentiate the types of procedures depending on the mechanism of their implementation, namely, according to the method of introducing a photosensitizer into the body. So, they distinguish:

• systemic therapy, when the drug in the form of tablets is taken 2,5 hours before the start of the UV irradiation process;
• a local procedure in which a substance is administered to the patient in the form of ointments and creams;
• PUVA baths: in this case, the patient takes baths with the active substance dissolved in water.

Drugs used in therapy

All photosensitizers that are used in PUVA therapy can be divided into two main groups:

• having a natural origin;
• synthetically derived substances.

The first group includes those preparations that are extracted from natural substances – umbrella plants, citrus fruits and legumes, for example, Ammifurin, Methoxsalen, or 8-methoxypsoralen. This active element is contained in the grains of the plant “amni big”. Absorption of the substance occurs in the upper parts of the digestive tract, excretion occurs mainly through the kidneys.

The group of synthetic drugs includes Trimethylpsoralen, which, however, is more often used to treat vitiligo.

Benefits of PUVA treatment for psoriasis

Half a century ago, for a patient with psoriasis, not only was it not possible to identify the causes that provoke the disease (which, however, has practically not changed today), but there was also no adequate and effective method to rid him of plaques that constantly cause discomfort.

With the invention of PUVA therapy, the treatment of psoriasis has made it possible to improve the patient’s condition in more than 80% of cases. At the same time, the first visual signs of improvement in the skin condition appear after 4-5 procedures. The duration of the achieved remission can last from six months to several years.

PUVA therapy for psoriasis has a small list of contraindications and is fairly well tolerated by most patients.

The treatment takes place in an outpatient clinic, in a clinic, so it can be carried out without interruption from study or work.

The therapy is not addictive, and after its completion, the affected person does not develop a withdrawal syndrome.

The cosmetological and aesthetic effect consists in the appearance of a light, even tan in the patient.

Indications and contraindications for the therapeutic technique using UVR

Indications for the appointment of a course of procedures is diagnosed psoriasis in any form. Does this mean that the method of treatment is suitable for all patients affected by this disease?

Like any therapeutic procedure, PUVA therapy has a number of contraindications. It is forbidden to carry out UV irradiation to patients with the following pathologies:

• hypersensitivity to methoxsalen;
• diseases associated with hypersensitivity to light exposure, such as lupus erythematosus;
• melanoma;
• severe heart disease.

Pregnant women are also prohibited from prescribing the procedure.

Patients with fair skin, those who have previously been exposed to ionizing radiation, patients with weak immunity, kidney failure, cancer and cataracts, PUVA therapy is prescribed in extreme cases, with great care.

How is the treatment carried out

The treatment process does not require placing the patient in a hospital, so the procedures are carried out in clinics, hospitals, private and specialized medical institutions.

With indicated systemic therapy, the patient takes tablets of a photosensitizing substance with lean food or with milk. After some time, he is located in a special apparatus, standing or lying down, where he is subjected to UV radiation. The first procedure usually lasts a few minutes, and the time of subsequent procedures gradually increases.

The dosage of radiation is calculated taking into account the type of skin. To check the required dose of UV waves, doctors conduct the following experiment: several small areas of the skin are irradiated, gradually increasing the duration on each. After two or three days, the doctor evaluates the reaction of the skin, and prescribes a dose for the treatment of psoriasis, half as small as the one that caused the slightest redness.

After the procedure, during the next day, the patient must wear sunglasses to prevent the development of cataracts.

Usually, the course of systemic therapy lasts 10-30 procedures, depending on the initial condition of the person. Procedures are carried out with an interval of 1 day.

Exit from therapy occurs gradually – the patient is gradually reducing the dosage of photosensitizers each time.

PUVA baths are a more modern method of photochemotherapy. Psoralen dissolves in water, and the patient is immersed in the resulting liquid for a while, after which he is exposed to ultraviolet light, usually about 15 minutes. This method of treatment is offered to patients in whom the internal use of psoralens causes severe side effects, as well as to patients under 15 years of age.

PUVA therapy baths are especially effective for the treatment of psoriasis of the feet and hands. Thanks to this method of photochemotherapy, it is possible to reduce the course dose of radiation and minimize the likelihood of side effects.

The course of treatment with baths is 15-20 procedures, in advanced cases the doctor will recommend 30-40 sessions.

Local procedures are also carried out with the appointment of special ointments containing psoralens to the patient. Before being exposed to radiation, the patient applies the substance to the skin.

Side effects from PUVA treatment, possible complications after therapy

Despite the high efficiency and painlessness for the patient, PUVA therapy cannot be considered absolutely safe.

So, for example, taking photosensitizers in the form of tablets may be accompanied by some unpleasant sensations:

• nausea;
• skin itching and allergic manifestations on the skin;
• painful syndrome in the epigastric region;
• loss of appetite;
• dizziness;
• sleep disturbance;
• general depressed state;
• a decrease in blood pressure.

Typically, these symptoms appear after the first few doses of the drug, and eventually disappear.

To make their manifestations not so strong, the attending physician may recommend switching to fractional meals, taking the drug in portions, along with food, for example, with cereals or bakery products. The doctor may also prescribe antiemetic medications.

External use of psoralens can also cause discomfort:

• dryness and itching on the skin;
• allergic and contact dermatitis;
• erythema and burning.

To eliminate or soften them, the doctor may recommend the use of therapeutic ointments and creams, as well as bath products with peat oxidate.

Conducting courses of PUVA treatment in some cases can cause complications and some diseases, for example, keratitis, erythema, burning, premature skin aging, cataracts, burns, conjunctivitis, basal skin cancer, melanoma, squamous cell carcinoma. Repeated or too frequent courses of therapy especially increase the likelihood of their development.

Patients who undergo periodic PUVA therapy are advised to visit an ophthalmologist annually for an eye examination.

Factors contributing to getting rid of psoriasis

The treatment of this disease should be complex, since the very development of the disease is due to a combination of a whole range of factors. So, in addition to the use of PUVA therapy and drug treatment, doctors recommend introducing some restrictions in the daily diet – removing seafood, honey, citrus fruits, chicken meat, as well as vegetables, berries and fruits that have a red color from it. It is better to limit the use of canned food, fast food and semi-finished products, as well as any “synthetic” food, as it contains a large amount of harmful food additives.

When choosing clothes, it is recommended to give preference to cotton or linen fabrics, but not synthetics, which irritate the skin. From things made of natural animal wool, as well as fur products, it is also better to refuse.

For washing, you should choose products containing alkali, for example, special soap. Things during washing should be rinsed well in plenty of water.

It is better to choose bedding with hypoallergenic fillers that do not contain fluff, wool or feathers. Blankets, pillows and mattresses should be aired periodically.

When choosing furniture, you need to pay attention to the one that is made of natural materials and does not emit toxic formaldehyde fumes. All places and objects with abundant accumulation of dust – carpets, rugs, curtains, open shelves with various objects and books – must either be constantly wiped of dust or get rid of them. You need to be extremely careful when buying houseplants or pets.

Of course, the basic rule for a patient with psoriasis is cleanliness around. In a residential area, it is necessary to periodically do wet cleaning, ventilate, and also make sure that the air is not too dry or too humid.

Treatment of psoriasis at home with the use of photochemical exposure

PUVA therapy is available not only in medical institutions. To date, there are small portable devices that make it possible to conduct UV irradiation courses at home. In this way, locally located psoriatic plaques, for example, on the upper or lower extremities, are usually treated. It should be noted that the very fact that the procedure can be carried out at home does not mean that the patient in this case can self-medicate. All issues related to the duration and frequency of the course, determining the dose of the drug and radiation, the features of the procedure are decided by the attending physician, and only according to his appointment, PUVA therapy can be performed at home.

Reviews of psoriasis patients who have discovered PUVA therapy are mostly positive. Most of those affected note the high efficiency of photochemotherapy procedures. Indeed, treatment with a combination of taking photosensitizers and exposure to ultraviolet radiation makes it possible to achieve a long-term deep remission of the disease in just one course. The percentage of manifestation of side effects and harmful effects from photoradiation is quite small – no more than 20 out of 100 people report their appearance. Physicians also speak positively about the procedure – if you do not abuse the prescription of courses and dosage of UV radiation, as well as follow all preventive measures and precautions, the therapy is highly effective even in children and the elderly, especially in the fight against psoriasis of the upper and lower extremities.