Parapsoriasis

Parapsoriasis (blue morbus Brocq) is a clinically heterogeneous disease with an unexplained pathogenesis.

First described in 1902 Brocq. He combined three dermatoses into one group, having some common features: chronicity of the course, surface character of spotted scaly rash, absence of any subjective sensations and general phenomena, resistance to therapy.

[1], [2], [3], [4], [5], [6], [7]

Causes of the parapsoriasis

The causes and pathogenesis of parapsoriasis have not been fully studied. In the development of the disease, great importance is attached to the transmitted infections ( influenza, angina, etc.), the presence of foci of chronic infection (chronic tonsillitis, sinusitis, pyelonephritis, etc.), vascular changes, immune disorders. Among the factors contributing to the development of parapsoriasis, there are immune disorders, allergic reactions, endocrine system dysfunctions, various infections and viral diseases that play an important role in acute varioliform parapsoriasis.

[8], [9], [10], [11], [12]

Pathogenesis

With histological examination, no specific changes are noted. All forms of parapsoriasis have spongio, acanthosis, mild parakeratosis. Vacuum dystrophy of basal layer cells, exocytosis, are characteristic. In the dermis, vessels are dilated, around them an infiltrate of leiimorphonuclear leukocytes, lymphocytes and histiocytes. In acute parapsoriasis, hyperkeratosis, acanthosis, vacuolar degeneration of Malpighian network cells with formation of intraepidermal vesicles in some cases; in the dermis - dense perivascular infiltrate with a predominance of lymphocytes; sites of tissue destruction with the formation of necrotic crusts.

Pathomorphology of parapsoriasis

In the fresh elements of plaque parapsoriasis, edema of the papillary layer of the dermis, focal lymphohystiocytic infiltrates of different intensity, in the epidermis - focal parakeratosis, small acanthosis with focal extracellular edema and exocytosis. Vessels, as a rule, are dilated, the endothelium is swollen, lymphohystiocytic elements are revealed around them.

With a large-branched version, changes in the skin are more pronounced. The infiltrate is more dense, lymphohistiocytic, with pronounced epidermotropism, sometimes with the formation of intra-epidermal cavities filled with infiltrate cells. When studying the composition of the infiltrate with large-plaque form of parapsoriasis using electron microscopy and cytophotometry Raznatoiskim (1982) showed that it contains many undifferentiated lymphocytes and very active histiocytes, with atypical histograms with cytophotometry with an average DNA content higher than the diploid standard. S.E. Orfanos and D. Tsambaos (1982) found in the infiltrate of large-boned parapsoriasis the ultrastructural signs of Sesari cells (11 to 30%), found not only in the dermal infiltrate, but also inside the epidermis, which contact epidermal macrophages and epithelial cells. Such facts give grounds to these authors to attribute large-boned parapsoriasis to lymphoproliferative diseases.

With lichenoid parapsoriasis, the pathology of the skin resembles that of other forms, but differs in a more dense and band-shaped infiltrate consisting of lymphocytes, histiocytes and plasma cells in the upper part of the dermis. Characteristic are the enlargement and thickening of the venules, especially in the peripheral part of the infiltrate. The epidermis is somewhat thickened, marked exocytosis with the formation of parakeratotic foci and the stratum corneum. In electron microscopic examination, a significant number of atypical forms of lymphocytes reminiscent of Cesari cells were detected among the infiltrate cells, on the basis of which these authors refer this form, as well as the previous one, to lymphomas.

In acute lichenoid and varioliform parapsoriasis, thickening of the epidermis, focal parakeratosis, vacuolization and dystrophic changes of the prickly bed cells, often with the formation of intraepidermal vesicles and foci of necrosis, as well as reticular dystrophy with exocytosis of lymphoid and histiocytic elements are observed. In the dermis - lymphohistiocyte infiltrate, both perivascular, and merging. Significant changes are found in vessels in the form of vasculitis, perivasculitis with diapedesis of erythrocytes, sometimes thrombosis and necrotic changes in vascular walls. On this basis, some authors refer this form to vasculitis.

With drop-shaped parapsoriasis markedly expressed parakeratosis, spongiosis, which may resemble seborrheic eczema or psoriasis, however it differs from the latter by vacuolar degeneration of the basal cells of the epidermis and expressed exocytosis of the infiltrate cells. THEM. Raznatovsky (1982), with this form, found significant changes in the walls of the vessels of the surface network and perivascular, muft-reversed, predominantly lymphocytic infiltration. However, immunological studies have not confirmed the attribution of drop-shaped parapsoriasis to allergic vasculitis.

Lichenoid and plaque parapsoriasis differentiates from the initial stage of fungal mycosis. In the case of parapsoriasis, unlike mushroom fungi, moderate epidermal proliferation, monomorphic lymphohistiocytic infiltrate is found. In the dermis, there are no atypical cells in the infiltrate. Acute liohelic varioliform parapsoriasis due to the severity of vascular changes should be differentiated from allergic vasculitis, from which this form is distinguished by the absence in the infiltrate of neutrophilic granulopitites, fragments of their nuclei and fibrinoid deposits around the capillaries.

[13], [14], [15], [16]

Histogenesis of parapsoriasis

The immune genesis of some forms of parapsoriasis has been proved by immunomorphologic methods. So, using immunoperoxidase technique in combination with monoclonal antibodies, FM McMillan et al. (1982) found that in the infiltrate with plaque parapsoriasis there are T-lymphocytes, such as T-helpers and T-suppressors with a predominance of T-helpers. In acute lichenoid and varioliform parapsoriasis, circulating immune complexes, deposits in the walls of the vessels and in the basal membrane of the epidermis of the IgM and the C3 component of the complement were found, which served as the basis for assigning this form of parapsoriasis to immunocomplex diseases. It was found that in the infiltrate with this form the majority of cells are T-lymphocytes. And T suppressors predominate. These data suggest an important role of cell-mediated immune responses in the histogenesis of this form of the disease.

Symptoms of the parapsoriasis

Parapsoriasis often occurs in the spring and autumn. Clinically, traditionally distinguish four forms of the disease: teardrop, plaque, lichenoid and varioliform (acute). In the group of papular forms of parapsoria WN Meigei (1982) refers to lymphomatoid papulosis, which is now considered to be a pseudolymphoma.

There are separate observations of mixed parapsoriasis - teardrop and plaque, teardrop and lichenoid.

Plaque parapsoriasis

Depending on the size of the plaques, the benign small-plaque and the large-plaque parapsoriasis prone to transformation into lymphoma are distinguished. The surface of some lesions may appear atrophic, wrinkled, resembling crumpled tissue paper. There may be telangiectasia, de-and hypopigmentation, which gives the foci similarity to poikilodermia. Itching is usually absent. The appearance of itching, increased infiltration may be signs of the development of mushroom mycosis, other variants of lymphomas.

Dermatosis begins with the appearance of spots or slightly infiltrated plaques of pale pink color with a yellowish-brown tinge; their magnitude varies from 3 to 5 cm, the outlines are oval, round or irregular in shape. Foci of lesion, as a rule, are flat, do not rise above the level of the surrounding normal skin and are located on the trunk or extremities. Elements of the rash are not prone to fusion, on their surface there are finely lamellar or otrebusiform scales. Sometimes on the surface of lesions appear delicate wrinkles, reminiscent of crumpled tissue paper (pseudoatrophy). Subjective sensations are absent; sometimes there is a small fickle itch. Dermatosis proceeds chronically.

Teardrop-shaped parapsoriasis

This variety is manifested by the precipitation of numerous rounded nodules as large as lentil, pink or light brown in color. The center of the rash is covered with brownish-grayish scales. Elements of the rash are located on the skin of the trunk, upper and lower extremities, but may appear in other areas. With this form of parapsoriasis, three phenomena are observed: the phenomenon of the cachet (with careful removal of the scales it is completely separated), the phenomenon of latent peeling (when scraping the surface of the rashes it is possible to cause pancreatic peeling) and the symptom of purpura (with intense scraping of the rashes, there are pinpoint hemorrhages). Elements disappear without leaving a trace, sometimes leaving leukodermic patches. The disease can last for years.

Lichenic parapsoriasis

Lichenic parapsoriasis (syn: lichen variegatus, parapsoriasis variegata) is an extremely rare form, the main element of the rash is a cone-shaped papule of round or oval outlines, reddish-yellow or reddish-brown in color with a smooth, slightly shiny surface, sometimes covered with densely seated whitish flake. Rashes are arranged in the form of strips, which, crossing themselves, give the foci a networked character. The existence of this form is not recognized by all. A.A. Kalamkaryan (1980) shares the opinion of ST Pavlov (1960) and believes that lichenoid parapsoriasis is the initial form of vascular atrophic poikilodermia of Jacobi. Elements of the rash are often located on the trunk and extremities. Itching is usually absent. Lichenoidal parapsoriasis is highly resistant to therapy.

Mouth-Haberman's acute parsoriasis

Marsh-Haberman's acute parsoriasis (syn: acute lichenoid and autumn-like lichen, parapsoriasis lichenoides et varioliformis Mucha-Haberman) differs from other forms of parapsoriasis by the polymorphism of the rashes: there are bubble, papular, pustular, variceal, hemorrhagic eruptions, necrotic crusts occupying large areas of cutaneous cover, including the scalp, skin of the face, hands and feet. At the same time there may be typical for drop-shaped parapsoriasis elements. The disease begins acutely, in most cases regresses completely, leaving on the place of varioliform elements ciliated scars; less often after the disappearance of acute manifestations remains a pattern of drop-shaped parapsoriasis, which gave rise to a number of authors to consider varioliform parapsoriasis as a drop-shaped variant with acute course. At the same time OK Shaposhnikov and N.V. Dsmenkova (1974) and other angora consider it a form of allergic vasculitis. Acute parsoriasis of the Fly-Haberman begins acutely and quickly assumes a generalized character. Some dermatologists believe that acute parapsoriasis is a drop-shaped version with a sharp current. The clinical picture is characterized by polymorphism. Elements of rashes are scattered, symmetrical, not grouped. Simultaneously with typical eruptions, there are bubble, pustular, varicella-like elements, hemorrhagic nodules, necrotic crusts. After resolving the rashes, there are atypical atrophic scars. There are rashes on the mucous membranes of the genital organs and oral cavity. In some patients, there are prodromal manifestations in the form of general weakness, headache and malaise, subfebrile temperature and an increase in peripheral lymph nodes.

The transformation of plaque and lichenoid parapsoriasis into mushroom mycosis has been noted.

Differential diagnosis

Teardrop-shaped parapsoriasis is differentiated with psoriasis, secondary papular syphilis, red lichen planus and poikilodermia such as Jacobi; plaque parapsoriasis - with mushroom-like mycosis, seborrheic eczema, chronic skin trichophytosis; acute parapsoriasis - with chicken pox.

[17], [18], [19], [20], [21], [22]

Treatment of the parapsoriasis

With drop-shaped parapsoriasis, the centers of infection are sanitized. Prescribe broad-spectrum antibiotics, hyposensitizing, antihistamine, vascular (theonikol, komplamin) drugs. In chronic and subacute forms, the PUVA therapy is recommended in the resolution stage. If the effect of the above treatment is not effective enough, prescribe small doses of glucocorticosteroids.

Outwardly appointed local glucocorticosteroid, absorbable ointments.

With plaque and lichenoid parapsoriasis, the same treatment measures are carried out as in case of drop-shaped, but treatment presents significant difficulties.