Beginning >> Diseases >> Infectious >> Skin leushmaniosis

Skin leushmaniosis

Table of contents
Skin leushmaniosis
Clinic
Complications and forecast
Diagnosis
Treatment and prevention

Skin leushmaniosis — the natural and focal transmissible disease caused by different types of dermotropic leyshmaniye, which is characterized by damages of skin with ulcerations and the subsequent scarring.
The skin leushmaniosis has various names (see further in the text) depending on clinical features, a distribution zone.
Lat. — leishmaniosis cutanea.
English — cutaneous leishmaniasis.
Activators of a skin leushmaniosis on the morphological, cultural properties do not differ from activators of a visceral leushmaniosis. Their main difference — a dermotropnost, as defines features of a clinical current.
Different types of leyshmaniye, besides, are adapted to certain species of mosquitoes carriers and mammals (the main reservoir of an infection in the nature) in this connection strict endemicity is characteristic of leyshmanioz. Separate strains of leyshmaniye can differ on virulence degree. According to epidemiological features the skin leushmaniosis is divided into the following forms (fig. 1):
Классификация кожного лейшманиоза
Fig. 1
Classification of a skin leushmaniosis

Leyshmanioza of the Old World meet in the countries of East hemisphere; carriers — sort Phlebotomus mosquitoes.
Leyshmanioza of the New World carriers — sort Lutzomyia mosquitoes are registered in the countries of the Western hemisphere, and.
Gives an idea of clinical forms of an illness which can cause different types of dermotropic leyshmaniye of the New and Old World to tab. 1.

 Table 1. Clinical forms of leyshmanioz


Distribution zone

Leushmania

Skin

Diffusion
skin

Dermo
mucous

Old
Light

Zoonoza

L. major

+

L. aethiopica

+

+

+

Antroponoza

L. tropica

+

Mexican
complex

L. mexicana

+

+

L. amazonensis

+

+

New
Light

Brazilian
complex

L. venesuelensis

+

L, brasiliensis

+

+

L. panamensis

+

---

+

L, guyanensis

+

---

L. peruviana

+

 

 

This classification, apparently, cannot be considered final. In some regions (in particular, in Dominican Republic) also other types of leyshmaniye which place in modern classification is not defined are allocated, and features of a course of the pathology caused by them are studied.
The disease can proceed as the acute self-limiting process (for example, the leushmaniosis caused by L. major) or to get a chronic current (the leushmaniosis caused by L. tropica).
Approximate formulation of the diagnosis. Specification of the epidemiological anamnesis, supervision over features of a course of a disease help to formulate the diagnosis more accurately.         

  1. Skin leushmaniosis (Mexican), moderately severe current.
  2. Diffusion skin leushmaniosis (L. aethiopica), moderately severe current.
  3. Antroponozny leushmaniosis, recurrent form (lupoid type), heavy current.

Weight of a current at a skin leushmaniosis is defined by one of the following factors (or their set): plurality and nature of defeats, tendency to synchronization and recurrence, accession of consecutive infection.
Taking into account definition incubation interval duration "acute", "chronic" usually fall.
Pathogeny. At a sting of a mosquito promastigota get into skin, in the place of inoculation they quickly get in macrophages in whom, turning into amastigota, begin to breed actively. At the same time in macrophages are formed toxic for amastigot substances. In experiment it is proved that ability of macrophages to destroy leyshmaniye is defined substantially by amount of substances which products considerably increase in elicited macrophages. Believe that such parazitotsidny ability is genetically caused property of macrophages and its degree depends on a specific type of leyshmaniye.
In typical cases in a zone of penetration of leyshmaniye the huge number of the macrophages "stuffed" with amastigota accumulates. They are surrounded by lymphocytes and plasmocytes which quantity grows. As a result local granulematozny reaction forms. Further there is an elimination of parasitic cells, epithelial and colossal cells of Langkhans appear.
During active destruction of parasites products of their disintegration have direct effect on surrounding fabrics, derma blanket hypostasis, damage of collagen and elastin, and in some cases — their necrosis, in capillaries — hypostasis and proliferation of an endothelium, sometimes — a vasculitis with the subsequent obliteration of vessels is a consequence of what.
In forming of a local necrosis the essential role belongs to the cell-bound immune complexes which are formed as a result of emergence in blood of fragments (antigens) of the died leyshmaniye.
The pathogenicity of leyshmaniye is higher, the changes in fabric and vessels at release of parasitic antigen are expressed stronger. The characteristic local changes arising at various clinical forms of an illness reflect difficult relationship between parasites (their properties, quantity, activity of reproduction) and a human body.
At a skin leushmaniosis cellular hypersensitivity of the slowed-down type early forms that promotes subsiding of local process. More gradual increase of its activity promotes development of a diffusion skin leushmaniosis. At the same time in a zone of defeat the huge number of the infested macrophages and insignificant number of lymphocytes is found. Further from primary center such macrophages are carried by a blood flow on all organism, settling in a derma and creating the secondary centers. Stay of leyshmaniye in a blood channel is not followed by an internal injury as they do not possess a vistserotropnost. In some cases (the skin leushmaniosis caused, for example, L. mexicana) a leushmania can extend from primary center and limfogenno, creating near it small secondary small knots, and in some cases even causing emergence of regional lymphadenitis.

At the pathology caused by L. brasiliensis and L. panamensis mucous membranes of a nose and a stomatopharynx (a skin and mucous leushmaniosis) can be involved in process that is probably caused by features of activators. At the same time injury of mucous membranes, destruction of blood vessels quite often lead to damage of the sky and cartilages of a nose.
Remains not clear why further, despite the expressed cellular hypersensitivity and existence of the circulating antibodies, the spontaneous termination of pathological process is not always provided.
If recovery nevertheless comes, it as believe, is caused by generally cellular immunity, though other mechanisms which are studied so far are not excluded,
After the postponed disease durable (lifelong) immunity to that strain of leyshmaniye which caused a disease forms. However there are data that after the leushmaniosis caused by L. major there is an immunity and to L. tropica, a L. braziliensis creates immunity and to L. mexicana. It is still unknown whether the created immunity is sterile.



 
"Tick-borne spirochetosis   Whooping cough"