Skin Changes in Leprosy

Leprosy (leprosy, Hansen's disease) is a chronic infectious disease caused by mycobacterium leprae. Pathogen - mycobacterium leprosy. Not all people are equally receptive to them. It is no accident that before the discovery of the causative agent the main hypothesis of the development of the disease was hereditary. Men are sick more often. Negroes are more predisposed to leprosy, but the disease is easier for them. The disease is most common in India, Naples, Africa. More often leprosy become infected at the age of 10-20 years.

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

Causes of the pathogenesis of leprosy

The causative agent of the disease is a stick of leprosy - mycobacterium leprae. It is straight or slightly curved, acid-fast, 5 μm long, 0.5 μm thick. Does not grow in nutrient medium and in cell culture. The main reservoir is a man, in addition, there may be some wild animals: armadillos, a series of monkey monkeys, chimpanzees.

[6], [7], [8], [9], [10], [11],

Histogenesis of leprosy

In the development of the disease, great importance is attached to the violation of the state of cellular immunity and nonspecific protective factors against the background of pronounced hypersensitivity to mycobacteria leprosy, detected with the help of lepromine test. The presence of genetic conditionality of susceptibility (resistance) to the disease is evidenced by such data as significantly higher concordance of monozygotic twins in comparison with dizygotic, interracial differences in the manifestations of leprosy, different affection of relatives of patients with a similar probability of getting sick. An association of the disease with certain antigens of tissue compatibility (mainly HLA-B8, DR2, HLA-BW21) has been found, which may affect the nature of the immune response and, accordingly, the characteristics of the clinical picture. In patients with leprosy, a defect of macrophages is revealed, the consequence of which is their inability to convert the antigens of mycobacterium to immunogenic; imbalance of immunoregulatory cells, different in different forms of the disease. With the lepromatous type of leprosy, a subpopulation of lymphocytes with a suppressor-cytotoxic function predominates, there may be a defect in T-helpers, a cell-mediated delayed-type hypersensitivity reaction (a lepromine test negative) is practically not realized. It reveals the hyperactivity of B cells, a high level of antibodies, but without a protective role against mycobacterium leprosy. A.A. Yarilin (1999) draws attention to the dependence of the development of this or that form of lepra on the way in which the formation of immunity - on the humoral Th2-dependent (for lepromatosis) or on the Th1-dependent (for tuberculoid). In patients with tuberculosis leprosy, a subpopulation of T-helpers is predominantly detected, the lepromin test is positive, antigens to mycobacteria of leprosy are not detected. In the mechanisms of damage to the peripheral nervous system, the importance of autoimmune reactions is attributed to the antigenic generality of mycobacterium leprosy and neural tissue.

Symptoms of leprosy

Only man is sick with leprosy. In most cases, leprosy is infected from a person with leprosy. Infection occurs by airborne droplets, through the mucosa of the upper respiratory tract, damaged skin and, possibly, with the use of infected food and water. The incubation period is several years. Risk factors are:

• living in an endemic area;
• presence of sick relatives;
• contact with infected armadillos. Battleships are used to cultivate the pathogen: they develop leprosy granulomas (leproms).

The development of the disease depends on the state of specific cellular immunity. Leprosy pathogens multiply in peripheral nerves. In addition, they are found in many organs, where they are retained for a long time in endothelial cells and phagocytes. Only 20% of infected people get sick, which is explained by the weakness of cellular immunity.

Currently, several clinical types of leprosy are distinguished: lepromatous, tuberculoid, indeterminate and dimorphic. Lepromatous type is the heaviest and contagious type of leprosy, since in the lesions there is a large number of pathogens.

The disease is characterized by damage to the skin, mucous membranes, eyes, lymph nodes, peripheral nerve trunks, as well as the endocrine system and some internal organs, where granulomas and lepramatous infiltrates with a large content of mycobacteria leprosy are formed.

Skin manifestations are located on the skin of the face, the auricles, extensor surfaces of the extremities, buttocks, where there are erythematous, erythematous-pigment spots of various shapes and sizes that do not have precise contours. Over time, spots are infiltrated, protruding above the surface of the skin, and increase in size. On the skin both in the zone of infiltration and outside it also appear tubercles and nodes (leproms) in size from several millimeters to 2 cm, of a dense elastic consistency, cyanotic-brown or reddish-rusty color. Diffuse infiltration and leproms, located on the face (superciliary arches, cheeks, nose, chin) disfigure the patient, giving his face a kind of lion's face (facies leonina).

The hair of the eyebrows falls out from the outside. On the affected areas the skin becomes tense, the pattern is smoothed, the hair falls out. Then, a specific bilateral and symmetrical lesion of the peripheral nerves is noted, which leads to the disappearance of temperature, pain and tactile sensitivity. Often amazed elbow, middle, fibular, large auric nerves, the upper branch of the facial nerve. The nerve trunks are thickened, dense, smooth. Gradually develop trophic and motor disorders (lagophthalmus, paresis of masticatory and facial musculature, amyotrophies, contractures, trophic ulcers).

There is ulceration leprom. Ulcers usually have steep, sometimes undercut infiltrated margins, they can merge, forming extensive ulcerative defects that slowly heal with an uneven scar. Simultaneously with skin changes, the mucous membranes of the nose, larynx, and oral cavity are affected. Often the first signs of leprosy are the difficulty of nasal breathing and nosebleeds. The mucous membrane of the nose is hyperemic, edematous, on the surface there are multiple small erosions (lepromatous rhinitis).

Over time, atrophy of the mucous membrane develops and some leproms and infiltrations appear, mainly in the cartilaginous part of the nasal septum. Lepromes of different shapes and sizes of pale pink color, often ulcerate, which leads to deformation of the nasal septum, impeding nasal breathing ("flat-squared", "proboscis", "lorgnetny" nose, bulldog nose).

In severe cases, the mucous membranes of the lips, soft and hard palate, larynx, back of the tongue, etc., are affected.

Tuberculoid type

Tuberculoid type is marked by a lesion of the skin and peripheral nerves and is characterized by a benign course. In the foci of the lesion pathogens are detected with difficulty or, more often. Are absent. This type is characterized by the appearance on the skin of a few, various in form and size of erythematous spots, as well as papular elements, which are the main manifestation of the disease. They are often located on the face, neck, flexural surfaces of the extremities, back, buttock. Nodules usually small, flat, reddish-cyanotic, polygonal, prone to fusion into plaques with sharply contoured roll-like raised circular or polycyclic margin and peripheral growth. Over time, at the central part of the plaques, there are atrophy, hypopigmentation, peeling, andedge is preserved erythematous rim in width from several millimeters to 2-3 cm and more - figured tuberculoid. After themselves, the elements leave hypopigmentation or atrophy. In this type of lesion of peripheral nerve trunks is detected very early, sometimes to skin manifestations.

The ulnar, radial, peroneal nerves are most often affected, which manifests itself in a diffuse or distinctive thickening and soreness. Gradually this leads to the development of paresis, paralysis, finger contractures, atrophy of small muscles, skin, nails, mutilation of hands and feet ("seal paw", "hanging brush", "monkey's paw", "falling foot," etc.). There is a violation of temperature, pain and tactile sensitivity. The tendon reflexes decrease. In the foci of lesion, fat and sweating has been disrupted, there are no fuzzy hair.

Pathomorphology

Typical tuberculoid granulomas in the dermis, isolated or merging, form a tuberculoid type infiltrate, located mainly in the upper dermis, directly under the epidermis, sometimes involving it in the process. Granulomas consist of epithelioid cells surrounded by a small number of lymphoid elements, the environment of which can be seen giant cells of Pirogov-Langhans. Elastic network with the phenomena of destruction. This type of leprosy destroys small and larger nerve trunks that go along the vessels that are infiltrated with epithelioid and lymphoid elements. Characterized by significant hypertrophy of the skin nerves, surrounded, as a rule, by lymphocytes. Mycobacteria with this type of leprosy is very small or they are not found at all, but the lepromine test is positive. Appendages of the skin are almost completely destroyed or undergo atrophy, followed by replacement with fibrous tissue.

Undefined type

An indeterminate type is manifested by the appearance on the skin of only spotted rashes (hypochromic, erythematous, mixed, with geographical outlines). In the initial period, peripheral nerve damage is absent, and then a specific polyneuritis develops, leading to sensitivity disorders in distal limbs, amyotrophy of small muscles, finger contractures, trophic ulcers, etc.

Dimorphic type

In the dimorphic type, rashes on the skin and mucous membranes, characteristic of the lepromatous type, and a sensitivity disorder, as in the tuberculoid type of leprosy, are noted.

In the development of all types of leprosy, progressive, stationary, regressive and residual stages are distinguished. In clinical practice there is a transition of one type of leprosy to another, for example, tuberculoid into lepromatous type with the formation of borderline forms.

For all types of leprosy, but more often with lepromatous, internal organs (liver, spleen, adrenal glands, testicles) are affected, metabolic disorders (visceral amyloidosis), trophic ulcers are noted. Some patients have a lesion of the bone system (bone leproms, ossifying the periostitis of the tibia, elbows and other bones, resorption of the distal phalanges of the fingers and feet).

With leprosy, damage to the organs of vision is observed (episcleritis, keratitis, iritis, photophobia, lacrimation).

Diagnostic, prognostic and epidemiological value has a lepromine test (Mitsuda test). In the lepromatous type this sample is negative, tuberculoid (as well as in healthy individuals) - positive, and with dimorph or undifferentiated leprosy may be both positive and negative.

[12], [13], [14], [15],

Undifferentiated type of leprosy

The undifferentiated type of leprosy is characterized by the presence in the various parts of the skin, in addition to large folds, several hypochromic or erythematous lesions with reduced sensitivity.

Pathomorphology. In the dermis, lymphoid infiltration of the reticular layer of the dermis, predominantly perivascular, perifollicular and along the nerve trunks with the phenomena of intensive proliferation of neurolematocytes is detected. In addition to lymphocytes, the infiltrate contains histiocytes, pdasmocytes and eosinophil granulocytes. Infiltrates, gradually replaced by fibrous tissue, squeeze and partially destroy the appendages of the skin, nerve endings and nerve stems.

Similar changes, developing, can go to lepromatous or tuberculoid leprosy.

Lepromatous type of leprosy

The lepromatous type of leprosy is characterized by clinical polymorphism: erythematous spots, plaque-infiltrative foci and leproms. The spots are asymptomatic, plural, symmetrically located mainly on the face, extensor surface of the extremities, on the buttocks. They can merge, occupying almost the entire skin (so-called spotted leprosy). Spots exist for a long time, then disappear or infiltration or leproms develop in their zone. Infiltrative foci may take the form of limited plaques or diffuse lesions with blurred boundaries, a characteristic brownish-cyanotic color. With diffuse changes, a picture appears on the face, similar to the lion's face (facies leonina). There are scleroderm-like, erysipelas, pellagroide changes, rashes resembling psoriasiform, seboroids, sometimes bullous eruptions such as pemphigus, herpetiform dermatitis. Lepromes (leprosy tubercle, knot) can be dermal and subcutaneous. They are hemispherical, to different degrees rise above the level of the skin. In the natural course of the disease, two outcomes are possible: resorption or superficial ulceration with the formation of atrophic hyperpigmented foci or scars, respectively. Typical for lepromatous type of leprosy is the damage to the mucous membrane of the mouth, nose, larynx, the development of leprosy neuritis. During periods of exacerbations of the disease (reactive phases), polymorphic eruptions can occur. The most characteristic of them is erythema nodosum (may ulcerate). Leprosy leprosy and histiosis leprosy are among the special variants of the lepromatous type of leprosy. With leprosy Luzio, the entire skin is diffusely altered, hyperemironan. There are multiple telangiectasias, there may be insignificant hyperpigmentation. Due to edema, infiltration, the skin becomes scleroderm-like, shiny. There may be extensive ulceration. The diagnosis of histone leprosy is based on histological examination (the presence of spindle-shaped histiocytes containing a large number of mycobacteria leprosy), clinical signs - sharply outlined plaques with steep edges, peeling and point impressions on their surface in the center.

Pathomorphology

The histological pattern in the lepromatous type of leprosy is quite typical, the granulomas are formed from histiocytes in various stages of development, with the formation of classical leprosy foam cells of Virchow, the cytoplasm of which contains a large number of mycobacteria leprosy and lipids, which appear in the coloration of Sudan III. Among these cells are exudate cells - lymphocytes and plasmocytes. Depending on the nature of the skin lesion, granulomas occupy a different volume of the dermis, being islands or narrow strands with superficial lesions and diffusely with deeper infiltrates and leproms. Between the cells of the infiltrate, sometimes there are giant Tuton cells, including phospholipids. In leprosy cells, the Russelean bodies, which are formed as a result of the destruction of nuclei, can be detected. Mycobacteria are located inside leprosy cells in the form of beams and globules, as well as around small vessels and in the secretion of sebaceous and sweat glands. The epidermis is usually flattened and atrophic, the epidermal outgrowths are smoothened as a result of the pressure of the infiltrate. It is often possible to see under the epidermis a strip of unaltered collagen separating it from a granulomatous infiltrate.

Involved in the process of blood vessels and nerves. The walls of the vessels are infiltrated by macrophage elements, the endotheliocytes swell, proliferate, and sometimes turn into leprosy cells. They, as a rule, contain a lot of mycobacteria leprosy, sometimes in the form of globules. Nerves are angled due to the stratification of the perineurium, contain a significant number of mycobacteria in all structures.

With diffuse lepromatous leprosy (the phenomenon of Lucio), in addition to the picture described above, necrobiotic changes in the epidermis, neoplasm of the vessels in the dermis, and significant infiltration of inflammatory elements of the subcutaneous fat, especially around large vessels.

In the future, necrosis of capillaries with secondary necrosis of the skin and ulceration may develop. Mycobacteria leprosy invade the walls of the vessels and even penetrate into their lumen.

In addition, lepromatous nodosum erythema is distinguished as a reactive form clinically similar to usual erythema nodosum, which is based on leprosy panniculitis. Characterized by acute inflammatory infiltration of not only the dermis, but also subcutaneous tissue with leprosy cells with an admixture of lymphocytes, neutrophilic granulocytes and plasmocytes. This type of lepromatosis is characterized by neutrophilic leukoclastic vasculitis with eosinophilia, fibrinoid changes in the walls of vessels with subsequent hyalinosis. Small leprosy granulomas containing mycobacteria leprosy are found in the dermis and subcutaneous tissue.

Edge type

The borderline group of leprosy is characterized by signs of polar types with a predominance of vesicular elements of tuberculoid or lepromatous leprosy. Clinical peculiarity of the borderline ("dimorphic") leprosy itself is the presence of "punctured" or "stamped" spots and plaques, curbs arising as a result of uneven regression of the process in different areas of vysypnyh elements. Multiple asymmetric neuritis is common.

Pathomorphology

Along with the foci of the tuberculoid structure, there are clusters of a significant number of histiocytes with pronounced signs of leprosy cells, located diffusely in the upper part of the dermis, but not penetrating the epidermis. In the reticular layer the infiltrate is localized mainly near the appendages of the skin, as well as in the lepromatous type of leprosy, destruction and infiltration of the muscles lifting the hair can be observed. Skin nerves are destroyed to a lesser extent, but their number is reduced, and the emerging bundles are thickened and infiltrated. As a rule, large nerve trunks are affected, in which infiltrate cells, mainly lymphocytes, as well as mycobacteria leprosy in the form of beams or globules are found.

[16], [17], [18], [19], [20], [21], [22], [23]

Differential diagnosis of leprosy

A differentiated diagnosis is made with syphilis, vitiligo, toxicodermia, tuberculosis lupus, and others.

[24], [25], [26], [27], [28], [29], [30], [31],

Treatment of leprosy

Treatment is complex, conducted in leprosariums. It is recommended to conduct specific, restorative therapy. Vitamin A, C, group B, pyrogenic preparations, antioxidants, methyluracil and others are used as restorative agents. Dapsone is used from anti-prosthetic drugs (in tablets or powders, 50-200 mg per day or oily suspension in the body 1-2 times per week), a 50% solution of solesulfone sulfetron (w / m 2 times a week starting at 0.5 ml and increasing gradually a single dose to 3.5 ml), ciba-1906 (tablets from 0.5 to 2 g in day or as an oil suspension intramuscularly from 2 to 6 ml once a week), protionamide (0.25 grams 1-3 times a day), lamprene - 100 mg (1 capsule) zhednevno, rifampicin (in 2-4 or 300-600 mg capsules). Assign also diucifon, dimotsifon.