Psoriasis therapy: doctor's options

Arkady Frankenberg, Ph.D., Associate Professor, Chief Physician of the Dnepropetrovsk Regional Dermatovenerological Dispensary, member of the European Academy of Dermatology and Venereology.

Psoriasis (scaly lichen ) is a common disease, its frequency among the general population of the world ranges from 2 to 4%. Psoriasis is a chronic disease, usually characterized by an undulating course, with periods of remissions or improvements, spontaneous or caused by certain therapeutic interventions, as well as periods of spontaneous or provoked by adverse external influences (alcohol consumption, intercurrent infections, stress) relapses or exacerbations.

There is now consensus among scientists that psoriasis is an immune disease and is mediated by T cells. The hereditary theory of the disease is very popular, and it is based on the following statistics: approximately 60% of patients have psoriasis in their parents or close relatives. However, research shows that it is not the disease itself that is inherited, but only the predisposition to it.

The clinical manifestations of psoriasis are quite characteristic, and making the correct diagnosis is not particularly difficult. The main skin manifestation of the disease is a pink papule (of varying intensity), covered with silvery-white, finely lamellar scales. Typical locations for psoriatic rashes are the extensor surfaces of the extremities (especially in the area of the knee and elbow joints), the sacrum, and the scalp.

During a clinical examination of the elements of the rash, one can observe the so-called “psoriatic triad” in the form of phenomena that appear sequentially when scraping:

• the phenomenon of stearin stain - scales similar to a crushed drop of stearin;
• terminal film phenomenon - a moist, shiny, red surface forms on the papule;
• the phenomenon of dotted dew - small droplets of blood appear on the surface of the papule.

A characteristic clinical manifestation is the Koebner symptom - the appearance of psoriatic rashes in places of injury or irritation of the skin.

The following clinical forms of psoriasis are distinguished: vulgar, guttate, intertriginous, inverse, pustular, palmoplantar pustulosis, persistent purulent acrodermatitis Allopo, psoriatic onychodystrophy, psoriatic arthropathy.

There are three stages in the development of the disease.

1. Progression of the process in which rashes up to 1-2 mm in size appear in large numbers in new areas. Subsequently, they transform into typical psoriatic plaques.
2. The stationary stage is the absence of the appearance of “fresh” elements, maintaining the size and appearance of existing plaques, completely covered with exfoliating epidermis.
3. The regression stage is a reduction and flattening of plaques, a decrease in the severity of peeling and the disappearance of elements, the resorption of which begins in the center. After their complete disappearance, foci of depigmentation usually remain.

The disease can manifest itself in a variety of ways, from mild forms with single plaques to severe conditions accompanied by damage to large areas of the body. But, regardless of the location, type and forms of pathology, there are a number of general principles for the treatment of psoriasis, adherence to which will significantly improve the patient’s condition.

General principles of European guidelines for the treatment of psoriasis

1. Strict adherence to complex therapeutic treatment algorithms.
2. Constant monitoring by a specialist dermatologist of the disease’s response to the medications prescribed to the sick patient.
3. Timely modification of therapy in case of ineffectiveness.

The choice of drugs and treatment methods is directly dependent on the severity of the disease. In mild and moderate cases, it is possible to limit it with local agents; in severe forms, the use of systemic therapy is necessary. To objectify the determination of the severity and activity of psoriasis, several indices are used, the most common of which is the PASI index (the Psoriasis Area and Severity Index). A PASI index of less than 10 indicates a mild course of the disease, and more than 10 indicates moderate or severe disease.

To treat the disease, systemic therapy is necessary.

Immunobiological therapy

In recent decades, with the development of molecular biology and immunology, it has become possible to create highly targeted biological drugs that selectively act on certain mechanisms without affecting other components of the immune system.

In psoriasis, an extremely effective mechanism is to reduce elevated levels of TNF-alpha by binding it to a specific artificially created antibody. When TNF-alpha is eliminated, the cascade of immunological reactions is broken and the process stops. Modern TNF-alpha inhibitor drugs are well tolerated and easy to administer.

There are three drugs available for immunobiological therapy in Ukraine: Adalimumab, Infliximab, Ustekinumab. Unfortunately, the high cost sharply limits their widespread implementation in the treatment of severe forms of psoriasis, including arthropathic.

Methotrexate

Methotrexate for the treatment of psoriasis represents a classic model of systemic treatment. This is especially true for severe cases of psoriasis, including pustular and erythrodermic forms, psoriatic osteoarthritis. Methotrexate is a cytostatic drug that can suppress the accelerated division of skin cells in psoriasis.

The drug is an analogue of folic acid and is capable of inhibiting dihydrofolate reductase, and depending on the dose, it interferes with the synthesis of DNA, RNA, thymidine purine and protein. The cytostatic mechanism affects lymphocytes and hyperproliferative keratinocytes, which are critical in psoriasis.

Phototherapy

The following are used to treat psoriasis:

• photochemotherapy (PUVA) - a combination of long-wave ultraviolet irradiation and an internal photosensitizer;
• selective phototherapy - a combination of medium-wave radiation (295-330 nm) and long-wave ultraviolet irradiation;
• narrow-wave UVB therapy with an emission peak at a wavelength of 311 nm.

The photoimmunological effect of light therapy is determined by the depth of penetration of ultraviolet rays. UVB rays affect mainly epidermal keratinocytes and Langerhans cells, while UVA rays penetrate deeper layers of the skin and affect dermal fibroblasts, dendritic cells and inflammatory infiltrate cells. UV rays affect the production of cytokines that have an immunosuppressive effect, the expression of molecules on the cell surface and the induction of cell apoptosis, which may explain the therapeutic effect of ultraviolet radiation.

In our opinion, phototherapy is one of the most effective and affordable methods of treating moderate and severe forms of psoriasis (photo 1-2) .

Local therapy

Local therapy plays a leading role in the treatment of mild, limited forms of psoriasis. For a long time, preparations containing salicylic acid, urea, and tar have been used.

Vitamin D preparations and its analogues (calcipotriol, tacalcitol, calcitriol) are very effective. It should be remembered that these drugs can interfere with systemic calcium metabolism, leading to hypercalcemia and hypercalciuria. Therefore, dosage restrictions must be strictly observed.

Topical corticosteroids remain relevant.

Glucocorticosteroids in the treatment of psoriasis suppress all stages of inflammation, have an antitoxic effect and an immunosuppressive effect. Pharmaceutical companies are trying to diversify the range of dosage forms and produce GCS in the form of ointments, creams, and lotions.

• Fatty ointment, creating a film on the surface of the lesion, causes more effective resorption of infiltration than other dosage forms.
• The cream better relieves acute inflammation, moisturizes, and cools the skin.
• The fat-free base of the lotion ensures its easy distribution over the surface of the scalp without sticking the hair.

Patients are attracted by the ease of use of steroid drugs, the ability to obtain a sufficient clinical effect, affordability, and lack of odor. However, their use should be short-term to avoid the development of local complications. Continuous use of corticosteroid ointments for up to one month is considered safe. Abrupt withdrawal of corticosteroids after long-term use can cause an exacerbation of the skin process - the so-called “withdrawal syndrome”.

Treatment of psoriasis still remains a serious medical problem, but the doctor has many effective and safe treatment methods in his arsenal that can significantly reduce the symptoms of the disease, and sometimes achieve complete and long-term remission.

First published in Cosmetologist 6/2016