American mucocutaneous and skin leishmaniasis

In the Eastern Hemisphere, the causative agents of cutaneous leishmaniasis are parasites of the L. Tropica complex; the disease is often called the eastern ulcer. In the Western Hemisphere, the causative agents of this form of the disease are represented by the leishmania of L. Mexicana and L. Brasiliensis complexes. Some parasites of the L. Brasiliensis complex can spread along the lymphatic pathways.

A part of people affected by L. Aephiopica and some species of the L. Mexicana complex develop diffuse cutaneous leishmaniasis; while due to specific disorders in the system of cellular immunity amastigot continue to proliferate, and the epidermis does not ulcerate.

Diagnosis and treatment of cutaneous leishmaniasis in America is carried out by the same methods and with the help of the same drugs as with skin leishmaniasis of the Old World.

Worldwide, 90% of all cases of skin and mucocutaneous leishmaniasis occur in Brazil, Peru, Algeria, Saudi Arabia, Syria and Iran.

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

Cutaneous leishmaniasis of the New World of L. Mexikana complex

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

Causes

The causative agent of cutaneous leishmaniasis of the New World is L. Mexikana, which includes 5 subspecies of leishmanias.

The Mexican form of leishmaniasis is found in southern Mexico (the Yucatán Peninsula), Guatemala and in neighboring countries. It is a zoonosis, natural foci of which are associated with the landscapes of moist tropical forests. More often there is one leishmanioma, mainly on the skin of the ear, which heals without complications. However, cases (about 40%) of the chronic course of the disease with the formation of deep ulcers and the destruction of the cartilaginous tissue of the ears, nose and larynx are not uncommon.

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

Epidemiology

Most forms of this disease are natural focal zoonoses. Sources and reservoirs of pathogens can be rodents, marsupials, many wild and domestic animals. The main carriers are mosquitoes from the genera Lutzomyia and Psychodopygus, many species of which in their biotopes attack a person during the daytime, during production activities. The disease is prevalent mainly in rural areas, in cities it is found as an exception. The maximum number of cases is accounted for by. Rain season. The susceptibility is universal (sick people of all ages, both local and foreign). The disease is recorded in all countries of Latin America (possibly, with the exception of Chile), in the southern regions of the United States (Texas).

In Brazil (the Amazon basin), L. Mexicana amazonensis is excreted, affecting mostly wild animals (rats, mice, opossums, foxes, packs) that live in the forest, on river banks and in wetlands. Man is included in the epidemic process extremely rarely. In case of infection, the disease in a person is very difficult, in 30% of cases it is not amenable to treatment, in the form of diffuse cutaneous leishmaniasis leads to disfigurement.

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

Pathogenesis and pathoanatomical picture

Pathogenesis in many ways pathogenesis is similar to that in skin Leishmaniasis of the Old World. Deeper damage to the skin (up to the hypodermis) and a relatively frequent spread of the pathological process to the mucous membranes (up to the submucosa) of the nose, mouth, pharynx, larynx, and rarely - genitals are noted. Immunity is unstable and unstressed.

Symptoms

The incubation period lasts from 2-3 weeks to 1-3 months. There are no fundamental differences in the clinical picture of skin lesions in leishmaniasis of the New and Old World.

When the first ulcer is usually deeper, they are sometimes accompanied by lymphangitis and lymphadenitis. The most important feature of cutaneous leishmaniasis of the New World is the frequent involvement in the pathological process of the mucous membranes. Typically, the mucous membranes are affected 1-2 years after the development of ulcers on the skin. Ulcers and necrotic changes on mucous membranes lead to deep deformations of the nose, ears, nose of the pharynx, respiratory tract, genital organs, disfiguring and disabling patients.

Several forms of cutaneous leishmaniasis of the New World are known.

In Mexico, this disease is called the ulcer of "chicles" - collectors of rubber juice, about 30% of which fall ill in the first year of work in the forest. The disease usually occurs in a relatively mild form. More often one leishmanioma appears on open, mosquito-accessible parts of the body, which heals without complications in a few months. With the localization of lesions in the auricle, which is noted in 40% of cases, the disease takes a long chronic course and leads to deformation of the auricle. Mucous membranes are not affected. However, isolated cases are known when deep ulcers develop with the destruction of the cartilaginous tissue of the nose.

Pathogens are found in the ulcer only during the first three months of the illness.

Cutaneous leishmaniasis caused by other representatives of the complex L. Mexicana - L. Mexicana amazonemis and L. Mexicana pifanoi

Cutaneous leishmaniasis caused by other representatives of the complex L. Mexicana-L. Mexicana amazonemis and L. Mexicana pifanoi, often leads to the development of diffuse cutaneous leishmaniasis. Clinically, it resembles the diffuse cutaneous leishmaniasis of the Old World, poorly treatable, and most often recorded in the Dominican Republic

Diagnosis and prevention

Diagnosis and prevention are the same as with skin leishmaniasis of the Old World.

[23], [24], [25], [26]