The beneficial effect of solar illumination on many skin diseases was known even to ancient medicine. However, in the issue of skin irradiation with natural UVBs, 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 is the disease and how is it dangerous
Psoriasis is a non-infectious lesion of the skin. The main symptom that characterizes it is specific psoriatic plaques that gradually replace the area of healthy skin. 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 because approximately 70% of all cases of the disease occur in people aged 15 to 25 years.
The astonished person draws attention to the appearance of itchy and scaly areas of skin that rise, as it were, above the healthy skin integuments - psoriatic plaques. These plaques, themselves pronounced red, covered with a white coating, like a thin layer of wax, may have whitish scales.
Education can cover the skin throughout the body, but most often found in places of bend and friction of the skin: on the buttocks, knees, feet, elbows and knees. In addition, the lesion is often localized in the scalp, around the ears, on the hands and around the nails, in the region of the external genital organs.
The area of a plaque can be insignificant - the size of a match head, or extend to the entire surface of a part of the body. Lesions are rarely solitary, and if a psoriatic plaque is found anywhere on the body, it is most likely that it did not appear alone. In addition to the characteristic appearance, the development of plaque is accompanied by severe itching and peeling. When combing, scales are separated from its surface. Sometimes a crack or suppuration may appear at the site of a 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 Kebner 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 of the nails.
The most common are two forms of psoriasis:
- summer, when the disease manifests itself due to sunlight, and exacerbations occur in the summer season;
- winter, when the skin reacts to a sharp cold by the development of psoriatic lesions.
One of the dangers of psoriasis lies in the fact that medicine is still not reliably unknown causes of its occurrence. Among the possible factors provoking the development of the disease, are called:
- genetic causes;
- autoimmune disorders;
- neurological pathology;
- metabolic disorders.
In fact, psoriasis does not cause any significant danger to the state of health or life of the affected, but 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 method of treatment by PUVA therapy is the use of a special photoactive substance that is used externally or ingested. In parallel, controlled irradiation of the skin by long-wave ultraviolet radiation occurs. In addition to complex cases of psoriasis, PUVA is prescribed to combat such diseases:
- atopic dermatitis;
- mushroom mycosis;
The scientific study of the properties of ultraviolet for human skin was first started in the late 19th century by the Danish Niels Finsen. Using coal arc lamps, this scientist first tried to use UVI to treat lupus erythematosus. In 1896, the Finsen Institute of Phototherapy was founded in Copenhagen. During the first five years of its existence, about 800 people were treated in it, 400 of whom got rid of their ailments.
In 1902, French engineer Gustav Pier Truve began designing a portable device of concentrated ultraviolet radiation for the treatment of skin diseases. Over the next 70 years, treatment with UV rays was, in some ways, experimental, and it was only in 1974 that the first source of intense UV radiation was developed, which allowed doctors to control the radiation dose, thereby saving patients from the negative effects of therapy.
Further, this method of dealing with skin ailments gradually began to be introduced everywhere. Beginning in 1978, it was actively used first in the USA, and later in Europe, for the treatment of psoriasis and other skin lesions. The statistics 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. Getting into the skin cells, the photoactive drug psoralen is activated only when exposed to ultraviolet rays of a certain length. In such an active state, they interact with the DNA of the cells of the epidermis, resulting in selective inhibition of DNA synthesis in the epidermal cells, but the functions of the cells are not suppressed.
One and a half hours after taking the photoactive drug, photochemical DNA binding occurs due to 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 the process of creating crosslinks of the “DNA-psoralen” type, which reduce the synthesis of the DNA of epidermal cells, that is, directly affect the causes of psoriatic plaques.
The provocation of arachidonic acid metabolism occurs due to the formation of reactive oxygen species that damage the membranes of the 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 to combat skin diseases, including psoriasis.
Technique for the implementation of PUVA-therapy
Conducting 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 may be maximum at a wavelength range of 350-365 nm.
PUVA devices are produced in various modifications - the patient can stand or lie in the process, or receive a dose of exposure only to a specific part of the body, for example, on the head, feet, knees or elbows.
Apparatus for irradiation of the whole body, mainly installed only in the relevant medical institutions, 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 conduct, namely, the method of introduction into the body of the photosensitizer. So, 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 the patient is prescribed a substance 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 the treatment process
All photosensitizers that are used in PUVA therapy can be divided into two main groups:
- having a natural origin;
- synthetically produced substances.
The first group includes those drugs that are extracted from natural substances - umbrella plants, citrus and legumes, for example, Ammifurin, Metoksalen, or 8-methoxypsoralen. This active element is contained in the grains of the plant “Amni big”. The absorption of the substance occurs in the upper parts of the digestive tract, excretion occurs mainly through the kidneys.
The group of synthetic drugs is Trimethylpsoralen, which, however, is more often used to treat vitiligo.
Advantages of the PUVA-method for the treatment of psoriasis
Half a century ago, for a patient with psoriasis, not only was it not possible to identify the causes of the disease (which, however, practically has not changed at all), but there was no adequate and effective method to rid it of plaques that are constantly causing discomfort.
With the invention of the PUVA therapy method, the treatment of psoriasis made it possible to improve the condition of the patient in more than 80% of cases. At the same time, the first visual signs of an improvement in the condition of the skin 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 well tolerated by most patients.
The treatment takes place in an outpatient clinic, in an outpatient clinic, so it can be carried out without interrupting study or work.
Therapy is not addictive, and after it ends, the affected person does not develop withdrawal syndrome.
Cosmetological and aesthetic effect is the appearance of a patient a light even tan.
Indications and contraindications to therapeutic methods using UV
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 irradiate UV radiation in patients with such pathologies:
- hypersensitivity to methoxalene;
- diseases associated with hypersensitivity to exposure to light, for example, with lupus erythematosus;
- severe heart disease.
Pregnant women are also prohibited from prescribing the procedure.
Patients with fair skin, those who have previously undergone ionizing radiation, patients with weak immunity, renal insufficiency, cancer and cataract PUVA therapy is prescribed in extreme cases, with great care.
How is the treatment carried out?
The treatment process does not require the placement of the patient in the hospital, so the procedures are carried out in clinics, hospitals, private and specialized medical institutions.
With systemic therapy shown, the patient takes a photosensitizing tablet with a low-fat diet or milk. After some time, it is located in a special apparatus, standing or lying, where it is subjected to UV irradiation. The first procedure usually lasts a few minutes, and the time of the next gradually increases.
Calculation of the dosage of radiation takes into account the type of skin. To test the required dose of UV waves, physicians conduct this experiment: a few small areas of the skin are irradiated, gradually increasing the duration on each. After two or three days, the doctor assesses the reaction of the skin, and prescribes a dose for the treatment of psoriasis that is half as much as the one that caused the most insignificant redness.
After the procedure, the patient must wear sunglasses for the next day to prevent the development of cataracts.
Usually, a 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.
The withdrawal from therapy occurs gradually - the patient each time gradually reduces the dosage of photosensitizers.
PUVA baths are a more modern method of photochemotherapy. Psoralen is soluble in water, and the patient is immersed in the resulting liquid for a while, after which it is exposed to ultraviolet radiation, usually about 15 minutes. This method of treatment is offered to patients in whom the internal reception of psoralens causes strong side effects, as well as to patients younger than 15 years.
Especially effective baths PUVA-therapy 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 performed with the appointment of special ointments to the patient, containing psoralens. Before being exposed to radiation, the patient applies the substance to the skin.
Side effects of PUVA treatment, possible complications after therapy
Despite the high efficiency and painlessness for the patient, PUVA-therapy cannot be considered absolutely safe.
For example, taking photosensitizers in the form of tablets can be accompanied by some unpleasant sensations:
- skin itching and allergic manifestations on the skin;
- painful epigastric syndrome;
- loss of appetite;
- sleep disturbance;
- general depressed state;
- lowering blood pressure.
Typically, such 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 a fractional diet, taking the drug in batches, along with food, for example, with cereals or bakery products. The doctor may also prescribe antiemetic medicines.
External use of psoralens can also cause discomfort:
- dryness and itching of the skin;
- allergic and contact dermatitis;
- erythema and burning sensation.
To eliminate or mitigate 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 become the cause of complications and certain diseases, such as keratitis, erythema, burning, premature aging of the skin, cataracts, burns, conjunctivitis, basal skin cancer, melanoma, squamous cell carcinoma. Repeated or too frequent courses of therapy are particularly likely to enhance their development.
Patients who periodically undergo the procedures of PUVA therapy are recommended to visit an ophthalmologist annually to check their vision.
Factors contributing to getting rid of psoriasis
The treatment of this disease should be complex, since the development of the disease itself is due to a combination of a whole complex of factors. Thus, in addition to the use of PUVA-therapy and drug treatment, doctors recommend imposing some restrictions on the daily diet - remove seafood, honey, citrus fruits, chicken meat, as well as vegetables, berries and fruits that are red in color. It is better to limit the consumption of canned food, fast food and convenience foods, as well as any “synthetic” food, since 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. It is also better to refuse things from natural animal fur, as well as fur products.
For washing you should choose products containing alkali, for example, a special soap. Things should be rinsed well in plenty of water during washing.
Bedding is better to choose with hypoallergenic fillers that do not contain down, wool or feather. Blankets, pillows and mattresses must be periodically ventilated.
Choosing furniture, you need to pay attention to the one that is made of natural materials, and does not emit toxic fumes of formaldehyde. All places and objects of abundant dust accumulation - carpets, carpets, curtains, open shelves with various objects and books - must either be constantly cleaned from dust, or get rid of them. It is extremely necessary to treat the purchase of indoor plants or pets.
Of course, the main rule for a patient with psoriasis is cleanliness around. In a residential area, it is necessary to periodically do wet cleaning, airing, and also make sure that the air is not too dry or too humid.
Treatment of psoriasis at home with the use of photochemical effects
PUVA therapy is not only available in medical institutions. To date, there are portable devices of small size, which make it possible to conduct courses of UV irradiation at home. In this way, locally located psoriatic plaques are usually treated, for example, on the upper or lower extremities. It should be noted that the fact that it is possible to carry out the procedure at home does not mean that the patient can then self-medicate. All questions relating to the duration and frequency of the course, determining the dose of the drug and radiation, the specifics of the procedure are decided by the attending physician, and only for its intended purpose, PUVA therapy can be performed at home.
Reviews of patients with psoriasis, who discovered PUVA therapy, are mostly positive. Most of the patients noted high efficiency of photochemotherapy procedures. Indeed, treatment with a combination of receiving photosensitizers and exposure to ultraviolet radiation makes it possible to achieve long-term deep remission of the disease in one course. The percentage of side effects and harmful effects from photoradiation is quite small - no more than 20 people out of 100 report on their appearance. Doctors also speak positively about the procedure - if not abusing the appointment of courses and dosage of UV radiation, as well as to comply with all preventive measures and precautionary rules, therapy shows high efficiency even in children and the elderly, especially in the fight against psoriasis of the upper and lower extremities.