skin larva migrans
Introduction
Introduction to skin larval migration The term larvamigrans was first proposed by Beaver et al in 1952, when it was mainly referred to as toxocariasis. Over time, other worms such as the worm, the paragonimus in Sichuan, and other worms were also found. Larvae are the main form of parasitic in the human body and cause diseases. Larval migration can be divided into two types: skin larvae migration and visceral larval migration. Sometimes both can exist at the same time. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of infection: non-infectious Complications: systemic purulent infection
Cause
Causes of skin larval migration
Cause:
Skin larva migration is mainly caused by rash, which is caused by some larvae that are parasitic on animals such as cats and dogs, such as the worms of Ancylostoma braziliensis and A. caninum. The larvae of the hookworms of the human body such as the duodenal hookworm or the American hookworm can also cause the disease, and some nematodes such as the larvae of the Gnathostoma spinigerum can also cause rash.
(two) pathogenesis
When human skin is in contact with soil contaminated by animal waste, the infectious larvae invade from the skin, cannot penetrate under the germinal layer, and can only move between the dermis and the granules at a speed of several millimeters to several centimeters per day to produce sputum. The tunnel caused an immediate allergic reaction. The appearance of the tunnel was red and hard spots, local lesions appeared, and blisters formed. Histological examination revealed eosinophil infiltration around the tunnel.
Prevention
Skin larvae migration prevention
Strengthen health education and publicize parasite prevention knowledge.
Applying manure to crops to avoid barefoot work and contact with land.
Pay attention to personal hygiene, do not eat raw or unfamiliar freshwater fish.
Strengthen the management of animals such as cats and dogs to prevent cats and dogs from polluting water sources.
Complication
Skin larval transitional complications Complications, generalized purulent infections
The disease is usually accompanied by severe itching, so when the skin larvae migration is scratched by the skin, skin damage can cause bacterial infection, secondary purulent infection, for patients with low constitution and long-term use of immunosuppressive agents, infection can enter the blood circulation The formation of sepsis can be characterized by elevated body temperature, increased breathing, increased rhythm, increased blood levels, and positive blood culture.
Symptom
Symptoms of skin larval migration symptoms Common symptoms Itching crusting papules skin blisters, posterior...
When the nematode larvae invade the patient's skin and migrate, it can cause red papules and form irregular linear erythematous lesions, which can be bulged and blisters later. The patient has severe itching, because the larvae linger in the patient's skin. Line, its skin lesions can extend a few millimeters per day, while the old skin lesions can be crusted, and the migration of larvae can last for weeks, even months, often followed by purulent infection after scratching.
Examine
Examination of skin larval migration
Blood eosinophils usually increase. Transient infiltration of the lungs can be visualized by X-ray examination of the lungs.
Pathology: Animal larvae can not adapt to the human body, generally can not mature in the human body, and stay in the larval stage. therefore. No adult or insect eggs are visible in the human body; at the same time, the larvae cannot reach their normal parasitic sites, and atopic lesions are produced in the tissues and organs through which they migrate.
The larvae usually burrow in the granules or spines in the skin. There are round cells and eosinophils infiltrated in the skin near the tunnel, especially around the blood vessels. The nematode is slightly deeper in the skin, but the inflammatory response is basically the same.
Diagnosis
Diagnostic identification of skin larvae
Mainly based on clinical manifestations and epidemiological history, such as the history of contact with soil contaminated by animal manure, when the skin lesions caused by nematodes, the patient often has a history of eating raw or unripe freshwater fish.
This disease must be differentiated from the disease of the echinococcosis.
