Toxoplasmosis scleritis

Introduction to toxoplasmosis scleritis Toxoplasmosis is a widely distributed rodent infectious disease that was discovered in animals as early as 1908, and human cases were described in 1923. In 1939, a relatively in-depth study was conducted in a few countries, and the infection rate of people and animals has been found to be as high as 70% to 80%. Since 1969, significant progress has been made in the study of the life history of toxoplasma, which has promoted and accelerated the understanding of the disease. basic knowledge The proportion of sickness: 0.00001%--0.00006% Susceptible people: no specific population Mode of infection: parasitic infection Complications: total uveitis cataract optic discitis optic atrophy

Cause of toxoplasmosis scleritis

(1) Causes of the disease

The pathogen of toxoplasmosis is a parasitic protozoa called toxoplasma gondii, which belongs to the sporozoite protozoa, has three forms of trophozoites, cysts and oocysts. Its animal host is very extensive, and humans are only this parasite. Intermediate or temporary host, all animals closely related to humans (especially dogs and cats) can be the source of infection. Toxoplasma is not well understood for human infection. The main routes of transmission are congenital infections and acquired infections. Kinds of congenital infections in which the mother is infected with the toxoplasma through the placenta to infect the fetus; acquired acquired infections are more complex and are generally considered to be in contact with animal faeces containing oocysts, soil, through the mouth, skin infections; or secretions from affected animals Excreta such as saliva, nasal discharge, eye secretions, etc. are infected through various routes such as respiratory tract and trauma. Other potential vectors include blood transfusion, organ transplantation, laboratory and necropsy accidents.

(two) pathogenesis

The recurrence of congenital infection is caused by the rupture of the cyst for some reason. The acquired pathogen of the acquired infection is released from the cyst or body capsule of the host gastrointestinal tract and propagates in the gastrointestinal mucosa. The trophozoite flows through the bloodstream. Or lymphatic dissemination and infection of any nucleated cells in the host. If the host's immunity is low, it will continue to infect and cause local or systemic damage. If the host's immune function is good, the cysts will form, which are occult and have no obvious lesions. However, the body can produce humoral and cellular immune responses. If the body's resistance is reduced for some reason, the cysts and oocyst propagules will spread, leading to clinical symptoms of acute infection.

Toxoplasmosis scleritis prevention

Reduce contact with cats, dogs and other pets, especially pregnant women should pay attention.

Toxoplasmosis scleritis complications Complications, uveitis, cataract, optic discitis, optic atrophy

Whole uveitis, cataract, optic discitis, optic atrophy and extraocular muscle paralysis can occur.

Toxoplasmosis scleritis symptoms common symptoms jaundice tears blind spot lymph node enlargement

The main symptoms of congenital infection are based on meningococcal disease. There are still anemia, jaundice, various congenital anomalies and abortion caused by fetal death.

Most of the children infected with toxoplasma after birth, there are few symptoms of systemic infection, a small number of patients due to larval spread throughout the body, the common manifestations of fever 90%, lymph node enlargement 40%, discomfort 40%, there are liver, pneumonia, etc. .

Ocular diseases of toxoplasmosis generally only infringe on one eye, and retinitis occurs in 20% to 25% of children and adults with toxoplasmosis. This type of eye disease is almost caused by congenital infection, and almost no eye disease is caused by acquired infection after birth. Seekers may be caused by the activation of congenital potential lesions. The granulomatous choroiditis symptoms usually begin to appear at the age of 20 to 30 years. The lesions are single, which is the size of a disc. The degree of symptoms and visual acuity is determined by the retinal involvement. The location and extent of symptoms, blurred vision, blind spots, pain, photophobia, tearing, central vision loss, etc., strabismus is an early symptom of children, few systemic symptoms, acute active lesions are classified as old lesions There are two types of recurrent lesions and localized exudative lesions. Both types of clinical manifestations have retinal ambiguity, white or yellow cotton-like plaques on the edges of the protrusions, retinal edema and hemorrhage around, and exudation along the retinal vessels. Inflammatory exudation of the vitreous can make the fundus ambiguous. When the lesion is old, the lesion is atrophied with clear gray-white spots. And the dark spots of choroidal pigmentation, lesions can be in the peripheral and equatorial parts, but characterized by the occurrence of the vicinity of the posterior pole of the retina, often a variety of lesions ranging from old to new, but can also be a single, acquired acquired lesions It is characterized by localized retinopathy. In the posterior part of the fundus, there is grayish white or yellow-white tissue hyperplasia in the center of the old lesions. The surrounding ring is arranged in a zigzag pattern with dark brown pigment. The boundary with the normal retina is clear, and bleeding is rare. Toxoplasmosis is only It does not cause anterior uveitis. The clinical course of patients with toxoplasmic retinal choroiditis is unpredictable. It can be caused by one or more acute attacks, but usually stops after 40 years old. After the inflammation subsides, the visual acuity improves, but often does not completely recover. The author is accompanied by progressive vision loss.

Scleritis or scleral inflammation may be caused by the spread of severe toxoplasmic retinal choroiditis; or due to direct invasion of the toxoplasma or immune response to its metabolites, toxoplasmic sclerosing inflammation of the toxoplasmosis Reaction, sclera in the lesion area is inflammatory infiltration and swelling, purple red, forming inactive nodular bulge, nodular mass, pain rejection, nodules are more common, there are several nodules, may be associated with the presentation of scleritis .

Examination of toxoplasmosis scleritis

1. Serological examination method

Sabin-Feldman staining was performed in duplicate serum (acute phase and recovery phase). The indirect fluorescein-labeled antibody assay (IFA) was positive in the acute phase 1 to 2 weeks, peaked in 6 to 8 weeks, and the low titer was 1:4. ~1:64 terminal survival, it is currently considered that the enzyme-linked immunosorbent assay (ELISA) dilution is 1:8 positive for diagnostic value, IgM indirect fluorescein-labeled antibody appears on the 5th day after infection, the negative is faster than IgG, IgM from the initial Antibody stimulation until 3 years later or longer in the blood, so early diagnosis of acquired toxoplasmosis, must check whether IgM rises first and then decline, neonatal IgM antibody positive, suggesting fetal infection, because IgM can not pass Placenta, such as staining test, IFA and IgM antibodies are strongly positive, suggesting that the recent infection, such as staining test and IFA are negative, can rule out the disease.

2. Pathogen isolation

Animal inoculation methods are not commonly used clinically.

OCT examination can identify the posterior segment of the eye and retinopathy.

Diagnosis and diagnosis of toxoplasmosis scleritis

The diagnosis of toxoplasmosis is based on clinical manifestations, serological tests, trophozoites in tissues or body fluids, or toxoplasma from certain parts of the body. Which diagnostic test is most appropriate depends on the clinical situation.

Diagnosis of toxoplasmosis scleritis can be based on the detection of Toxoplasma gondii, serological reaction positive, clinical features of scleritis, but because of the difficulty in examining toxoplasma, serological positive and clinical features of scleritis are particularly important.

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