Vasculitides of the skin

Vasculitis (synonym: cutaneous angiitis) is a skin disease in the clinical and pathomorphological picture of which the initial and leading link is non-specific inflammation of the walls of skin vessels of different calibers.

Causes skin vasculitis

The causes and pathogenesis of vasculitis remain unclear to the end and it is believed that the disease is polyetiological. An important factor in its development is chronic infection, as well as tonsillitis, sinusitis, phlebitis, adnexitis, etc. Among infectious agents, the most important are streptococci and staphylococci, viruses, mycobacteria tuberculosis, some types of pathogenic fungi (genus Candida, Trichophyton mentagraphytes). Currently, the theory of immune complex genesis of vasculitis is becoming increasingly widespread, linking its occurrence with the damaging effect of immune complexes precipitated from the blood on the vascular walls. This is confirmed by the detection of immunoglobulins and complement in fresh lesions in patients with vasculitis. The role of an antigen can be played by one or another microbial agent, a medicinal substance, or one's own modified protein. Diseases of the endocrine system, metabolic disorders, chronic intoxication, mental and physical overstrain, etc. are of great importance in the pathogenesis of vasculitis.

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Risk factors

Changes in the skin vessels are mainly the result of inflammatory reactions of various origins involving the vascular walls (vasculitis). Vessels of various calibers are involved in the inflammatory process: small (capillaries), medium, large muscular, muscular-elastic and elastic types. Of the numerous causative factors of vasculitis, the most important are bacterial antigens, drugs, autoantigens, food and tumor antigens. Most often, vasculitis develops on the basis of immune disorders in the form of immediate and delayed hypersensitivity and their combinations, which can cause a variety of clinical and histological pictures.

In immediate hypersensitivity, vascular tissue permeability is sharply expressed, as a result of which the vessel walls in the inflammation focus are impregnated with protein fluid, sometimes undergoing fibrinoid changes; the infiltrate consists mainly of neutrophilic and eosinophilic granulocytes. In delayed hypersensitivity, cellular proliferative changes come to the fore, and the immune nature of the inflammation is confirmed by the presence of immune complexes in the vessels of the microcirculatory bed and in the cytoplasm of the infiltrate cells.

The tissue reaction mostly proceeds according to the Arthus and Sanarelli-Schwartzman phenomena. Immune complexes are found in the skin of patients, positive tests for various allergens, changes in cellular and humoral immunity, as well as reactions to vascular, streptococcal antigens are observed. Increased sensitivity to coccal flora, drugs, especially antibiotics, sulfonamides, analgesics are found. Factors contributing to the development of an allergic process in vasculitis are hypothermia, endocrine disorders (diabetes mellitus), neurotrophic disorders, pathology of internal organs (liver disease), intoxication and other effects.

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Pathogenesis

Usually the epidermis and skin appendages are unremarkable. Focal lesions of small vessels, mainly capillaries, are noted; in the lumens of the affected vessels there is an accumulation of segmented leukocytes, destruction of the vascular wall and cellular infiltration of the latter, as well as adjacent tissues. The infiltrate consists of segmented neutrophils, macrophages, lymphocytes and plasma cells. In places, multiple microthrombi are clearly visible. In more severe cases (in the presence of nodules), small arteries are affected.

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Symptoms skin vasculitis

The clinical picture of vasculitis is extremely diverse. There are a number of common signs that clinically unite this polymorphic group of dermatoses:

• inflammatory nature of changes;
• tendency of rashes to edema, hemorrhage, necrosis;
• symmetry of the lesion;
• polymorphism of morphological elements (usually they have an evolutionary character):
• predominant localization on the lower limbs;
• the presence of concomitant vascular, allergic, rheumatic, autoimmune and other systemic diseases;
• association of vasculitis with previous infection or drug intolerance;
• acute or periodically worsening course.

Hemorrhagic vasculitis of Schonlein-Henoch

There are cutaneous, abdominal, articular, necrotic, and fulminant forms of hemorrhagic vasculitis.

In the cutaneous form, the appearance of the so-called palpable purpura is noted - an edematous hemorrhagic spot of varying size, usually localized on the shins and the back of the feet, easily determined not only visually, but also by palpation, which distinguishes it from other purpuras. The initial rashes in hemorrhagic vasculitis are edematous inflammatory spots resembling blisters, which quickly transform into a hemorrhagic rash. As the inflammatory phenomena increase against the background of purpura and ecchymosis, hemorrhagic blisters are formed, after the opening of which deep erosions or ulcers are formed. The rashes are usually accompanied by mild edema of the lower extremities. In addition to the lower extremities, hemorrhagic spots can also be located on the thighs, buttocks, trunk and mucous membrane of the mouth and pharynx.

In the abdominal form, rashes are observed on the peritoneum or intestinal mucosa. Skin rash does not always precede gastrointestinal symptoms. In this case, vomiting, cramping pains in the abdomen, tension and pain on palpation are observed. Various pathological phenomena of varying degrees can also be observed on the part of the kidneys: from short-term unstable microhematuria and albuminuria to a pronounced picture of diffuse kidney damage.

The articular form is characterized by changes in the joints and their pain, which occur before or after the skin rash. There is damage to large (knee and ankle) joints, where swelling and pain are noted, persisting for several weeks. The skin over the affected joint changes color and has a greenish-yellow color.

The necrotic form of vasculitis is characterized by the appearance of multiple polymorphic rashes. At the same time, along with small spots, nodules and blisters filled with serous or hemorrhagic exudate, necrotic skin lesions, ulcerations and hemorrhagic crusts appear. The lesions are usually localized on the lower third of the shin, in the ankle area, and on the back of the feet. At the onset of the disease, the primary element is a hemorrhagic spot. Itching and burning are noted during this period. Then the spot quickly increases in size and is subject to wet necrosis from the surface. Necrotic ulcers can have different sizes and depths, even reaching the periosteum. Such ulcers last a long time and turn into trophic ulcers. Subjectively, patients complain of pain.

Forms

There is no generally accepted classification of allergic vasculitis. According to the classification of ST Pavlov and OK Shaposhnikov (1974), skin vasculitis is divided into superficial and deep according to the depth of vascular damage. In superficial vasculitis, the superficial vascular network of the skin is mainly affected (Ruiter's allergic vasculitis of the skin, Schonlein-Henoch hemorrhagic vasculitis, Miescher-Stork hemorrhagic microbead, Werther-Dümling nodular necrotic vasculitis, Roskam's disseminated allergic angiitis).

Deep vasculitis includes cutaneous nodular periarteritis, acute and chronic erythema nodosum. The latter includes Montgomery-O'Leary-Barker nodular vasculitis, Beufverstedt's migratory erythema nodosum, and Vilanova-Piñol's subacute migratory hypodermitis.

N.E. Yarygin (1980) divides allergic vasculitis into two main groups: acute and chronic, progressive. The author includes in the first group allergic vasculitis with reversible immune disorders, which occur more often once, but relapses without progression are possible (infectious, drug allergy and hypersensitivity to trophoallergens). The second group is characterized by a chronic relapsing course with progression of the process, which is based on difficult to reverse or irreversible immune disorders. These include allergic vasculitis in collagen diseases (rheumatism, rheumatoid arthritis, systemic lupus erythematosus, systemic scleroderma), systemic vasculitis, or vasculitis with immune disorders (nodular periarteritis, Wegener's granulomatosis, Buerger's disease, Henoch-Schonlein disease, etc.).

The classification of vasculitis by WM Sams (1986) is based on the pathogenetic principle. The author identifies the following groups:

1. leukocytoclastic vasculitis, which includes leukocytoclastic vasculitis; urticaria-like (hypocomplementemic) vasculitis, essential mixed cryoglobulinemia; Waldenstrom's hypergammaglobulinemic purpura; erythema persistent elevated and presumably special types - erythema multiforme exudative and lichenoid parapsoriasis;
2. rheumatic vasculitis developing in systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis;
3. granulomatous vasculitis in the form of allergic granulomatous angiitis, facial granuloma, Wegener's granulomatosis, annular granuloma, lipoid necrobiosis, rheumatic nodules;
4. periarteritis nodosa (classical and cutaneous types);
5. giant cell arteritis (temporal arteritis, polymyalgia rheumatica, Takayasu's disease).

The manifestations of the pathological process observed in patients do not always correspond to a particular variant of cutaneous vasculitis related to a certain nosological unit. This is explained by the fact that at different stages of the disease the clinical picture may change, symptoms characteristic of another form appear. In addition, the clinical picture depends on the individual reactions of the patient. In this regard, we believe that the allocation of individual nosological forms of allergic vasculitis is mostly conditional. In addition, this is confirmed by the fact that the pathogenesis of individual forms of allergic vasculitis and its morphological manifestations are very similar. Some authors have introduced the term necrotic vasculitis for allergic vasculitis of the skin.

Currently, there are several dozen dermatoses that belong to the group of skin vasculitis. Most of them have clinical and morphological similarities. In this regard, there is no single clinical or pathomorphological classification of skin vasculitis.

Classification of vasculitis. Most dermatologists, depending on the depth of the lesion, divide skin vasculitis into the following clinical forms:

• dermal vasculitis (polymorphic dermal vasculitis, chronic pigment purpura);
• dermo-hypodermal vasculitis (levodoangiitis);
• hypodermal vasculitis (nodular vasculitis).

These clinical forms are in turn subdivided into many types and subtypes.

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Differential diagnosis

The disease must be distinguished from hemorrhagic rashes in infectious diseases (measles, flu, etc.), liver diseases, diabetes, hypertension, vitamin C and PP deficiency, as well as other forms of vasculitis (hemorrhagic leukoplastic microbite, allergic arteriolitis, Werlhof's disease, etc.), erythema multiforme exudative.

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Treatment skin vasculitis

Bed rest and diet are necessary. If there is an infectious agent, antibiotics are prescribed. Antihistamines, hyposensitizing drugs, and drugs that strengthen the vascular wall (ascorutin, nicotine acid) are recommended. In the presence of anemia, blood transfusion is required. In severe cases, small or medium doses of glucocorticosteroids are prescribed orally. Antimalarial and nonsteroidal anti-inflammatory drugs may be effective.

Of the immunocorrective drugs, proteflazit is prescribed (15-20 drops 2 times a day), which increases the body's non-specific resistance and the production of endogenous interferon.

External treatment depends on the stage of the skin pathological process. For erosive and ulcerative lesions, disinfectant solutions are prescribed in the form of lotions, wet-drying bandages; enzyme preparations (trypsin, chemotrypsin) to remove necrotic tissue. After cleaning the ulcers, epithelializing agents and corticosteroids are applied. A helium-neon laser has a good effect.