Behcet's disease in adults

Behcet's disease (synonyms: major Touraine aphthosis, Behcet's syndrome, triple syndrome) is a multi-organ, inflammatory disease of unknown etiology, the clinical picture of which consists of aphthous stomatitis and lesions of the genitals, eyes and skin.

The disease was first described by the Turkish dermatologist Behcet in 1937. It is most common in Japan (1:10,000), in the countries of Southeast Asia and the Middle East. Behcet's disease most often affects men and most often affects people aged 20 to 40 years.

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Causes and pathogenesis of Behcet's disease

The causes and pathogenesis of Behcet's disease are not fully understood. It is assumed that the disease is of viral origin. Detection of antibodies in the blood serum and oral mucosa indicates the involvement of immune (autoimmune) mechanisms in the pathogenesis of the dermatosis. Familial cases of the disease, the presence of Behcet's disease in several generations in one family suggest the involvement of genetic factors in the development of the disease. A viral nature is assumed, the role of infectious-allergic, immune (autoimmune) disorders is shown. The importance of genetic factors cannot be ruled out, which may be indicated by descriptions of familial cases of the disease, including in twins. There is an association with blood group antigens HLA-B5, HLA-B12, HLA-B27, HLA-BW51, HLA-DR-2, HLA-DR-7, HIA-Cw2. Some believe that vasculitis underlies the disease.

Pathomorphology of Behcet's disease

The lesions are based on allergic vasculitis involving capillaries, venules and arterioles, the walls of which are infiltrated with lymphocytes and plasma cells. This is accompanied by proliferation of enlothiocytes, fibrin deposition in the vessel walls and in the surrounding tissue. In the active phase of the process, the number of tissue basophils increases in the upper parts of the dermis and in the subepithelial layer of the mucous membranes, secreting histamine, which increases tissue permeability. In the skin with a lesion of the necrotic pseudofolliculitis type, superficial areas of necrosis covered with a crust, dilated capillaries with swollen endothelium and subepidermal hemorrhages are found. An infiltrate of lymphocytes, plasma cells and tissue basophils develops around the epithelial hair follicles. In lesions of the erythema nodosum type, deep infiltrates and small hemorrhages are found, located in the dermis and subcutaneous tissue. In the infiltrate areas, homogenization and fragmentation of collagen fibers are found. In aphthous ulcers, lymphocytes, mononuclear cells and neutrophilic granulocytes are found, which contact epithelial cells along the edges of the ulcers. Epithelioid-cell histiocytic infiltrates in the form of tuberculoid structures are sometimes determined around necrotic areas.

The histogenesis of Behcet's disease has not been studied. The main role in the pathogenesis of the disease belongs to the antibody-dependent reaction to the epithelium of the oral mucosa. T. Kapeko et al. (1985) found IgM deposits in lesions, both aphthous and resembling erythema nodosum, as well as fluorescence with serum against streptococcal antigen in the walls of blood vessels and in the cells of the inflammatory infiltrate. Some studies indicate a viral etiology of the disease, in particular an association with the herpes simplex virus. Direct immunofluorescence reveals deposits of IgM and the C3 component of complement, located diffusely among the infiltrate cells and in the walls of blood vessels of deep lesions. IgG and IgA deposits are found only on the surface of aphthous ulcers. Immune complexes are present in the blood serum of patients. Scientists have found deposits of IgM, IgG and IgA in the vascular walls, associated with the C3 and C9 components of the complement, indicating an immune complex mechanism for the development of this disease. A reaction using monoclonal antibodies revealed a defect in T-lymphocytes. In the early stages of the disease, a decrease in the number of OKT4+- and an increase in OKTX+ cells in the peripheral blood were noted. At the same time, some patients showed activation of the B-cell link of immunity: there is information about the detection of anticardiolipin antibodies in the blood serum of patients.

Symptoms of Behcet's disease

The most common characteristic triad of symptoms is aphthous stomatitis, erosive and ulcerative lesions of the anogenital area, and eye changes. Skin changes are polymorphic: erythema nodosum type, pyogenic, nodular elements, acneiform, hemorrhagic rashes developing against the background of fever and general malaise. Less common are thrombophlebitis, meningoencephalitis, damage to the cardiovascular system and other visceral organs. The disease develops acutely, occurs in attacks, and the frequency of exacerbations decreases over time. The prognosis depends on the degree of damage to internal organs.

The clinical manifestation of Behcet's disease includes orogenital ulcers, skin lesions, anterior or posterior uveitis, arthralgia, neurological lesions and vascular thrombosis. The main symptoms are distributed in the following frequency: aphthous stomatitis (in 90-100% of patients), genital ulcers (in 80-90% of patients), eye symptoms (in 60-185% of patients). Next in frequency are thrombophlebitis, arthritis, skin rashes, damage to the nervous system, etc. Lesions of the oral mucosa are characterized by the formation of aphthous thrush-like erosions and ulcers of various shapes. They appear on the tongue, soft and hard palate, palatine arches, tonsils, cheeks, gums and lips and are accompanied by severe pain. Usually, the rash begins with a limited painful thickening of the mucous membrane, on which a superficial ulcer covered with fibrous plaque and then a crater-shaped ulcer with slight hyperemia around it is formed. The ulcer can increase in size to 2-3 cm in diameter. Sometimes the disease begins as a superficial aphtha, but after 5-10 days an infiltrate appears at the base of such an aphtha, and the aphtha itself turns into a deep ulcer. After healing, soft, superficial, smooth scars remain. There can be 3-5 lesions at the same time. Such aphthous lesions occur on the mucous membrane of the nose, larynx, esophagus, gastrointestinal tract. Lesions on the genitals consist of small blisters, superficial erosions and ulcers. On the male genitals, ulcers are located on the scrotum, at the root of the penis, and the inner thighs. The outlines of the ulcers are irregular, the bottom is uneven, covered with a serous-purulent coating, and the pain is pronounced. In women, painful ulcers, the size of a pea or 10 kopeck coin, are found on the labia majora and minora in large numbers.

Eye damage begins with periorbital pain and photophobia. The main symptom is damage to the retinal vessels, which ends in blindness. At the onset of the disease, conjunctivitis is observed, and later - hypopyon. In addition, iridocyclitis is observed. Without treatment, atrophy of the optic nerve, glaucoma or cataracts are observed, which lead to blindness. In Behcet's disease, both eyes are affected. Rashes in the form of nodular and multiform exudative erythema, nodules, pustules and hemorrhagic elements, etc. appear on the skin of the trunk and limbs. Superficial recurrent thrombophlebitis occurs in 15-25% of patients with Behcet's disease, and cardiovascular complications occur in 46%. In this regard, it is believed that Behcet's disease is a systemic disease based on vasculitis.

Usually the disease is accompanied by a severe general condition of the patient, fever, severe headache, general weakness, joint damage, meningoencephalitis, cranial nerve paralysis, etc. Periodically there is an improvement and even spontaneous remission, which is followed by a relapse.

Differential diagnosis

Behcet's disease should be distinguished from aphthous stomatitis, acute Chapin-Lipschutz ulcer, aphthous-ulcerative pharyngitis, Reiter's oculo-genito-urethral syndrome, and bullous erythema multiforme exudative.

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Treatment of Behcet's disease

Depending on the severity of the disease, corticosteroids, cytostatics, antibiotics are recommended separately or in combination. A pronounced effect is noted from taking colchicine (0.5 mg 2 times a day for 4-6 weeks), cyclophosphamide, dapsone. Disinfectant solutions and corticosteroid ointments are used externally.