Toxocarosis - Symptoms.

There are two main forms of toxocariasis - visceral and ocular. Some researchers suggest dividing toxocariasis into the following forms:

• visceral toxocariasis, including damage to the respiratory system, digestive tract, genitourinary system, myocardium (rare);
• CNS toxocariasis:
• muscle toxocariasis:
• cutaneous toxocariasis:
• toxocariasis of the eye;
• disseminated toxocariasis.

Symptoms of toxocariasis are the main criterion for dividing this disease into: manifest and asymptomatic toxocariasis, and by duration of the course - acute and chronic.

Visceral toxocariasis affects both children and adults, but this form is much more common in children, especially between the ages of 1.5 and 6 years. The clinical picture of toxocariasis is not very specific and is similar to the clinical symptoms of the acute phase of other helminthiases. The main symptoms of toxocariasis in the acute stage are recurrent fever, pulmonary syndrome, enlarged liver, polyadenopathy, skin manifestations, blood eosinophilia, and hypergammaglobulinemia. In children, the disease often develops suddenly or after a short prodromal period. Body temperature is often subfebrile (in severe cases of invasion - febrile), more pronounced during the period of pulmonary manifestations. Various types of recurrent skin rashes (erythematous, urticarial) are noted, Quincke's edema, Muscle-Wells syndrome, etc. may develop. Skin syndrome can persist for a long time, sometimes it is the main clinical manifestation of the disease. A study of children diagnosed with eczema in the Netherlands showed that 13.2% had high titers of specific antibodies to toxocara. Most of those infected, especially children, had moderately enlarged peripheral lymph nodes.

Respiratory system damage occurs in 50-65% of patients with visceral toxocariasis and can be expressed in varying degrees - from catarrhal phenomena to severe asthmatic conditions. The damage is especially severe in young children. Recurrent bronchitis and bronchopneumonia are possible. Patients note typical symptoms of toxocariasis: dry cough, frequent attacks of night coughing, sometimes ending in vomiting, in some cases severe expiratory dyspnea occurs, accompanied by cyanosis. Auscultation reveals scattered dry and moist rales of various sizes. X-rays reveal an increase in the pulmonary pattern, a picture of pneumonia; Cloud-like infiltrates are often detected, which, in combination with other clinical symptoms (fever, lymphadenopathy, hepatosplenomegaly, cutaneous allergic syndrome, hypereosinophilic leukocytosis), allows the diagnosis of Löffler syndrome to be made. One of the most serious problems associated with toxocariasis is its relationship with bronchial asthma. It has been shown that in 20% of patients with atopic bronchial asthma, occurring with hypereosinophilia, antibodies to the toxocariasis antigen (immunoglobulins of classes G and / or E) are detected.

Hepatomegaly is registered in 40-80% of patients. The liver is compacted, smooth, often tense on palpation, while the spleen is enlarged in about 20% of patients. The predisposing role of toxocara in the development of pyogenic liver abscesses has been established, which can be both single and multiple, located in both lobes of the liver. Abdominal syndrome is observed in 60% of cases. Characteristic are abdominal pain, bloating, nausea, sometimes vomiting, diarrhea.

In the chronic stage of toxocariasis, there are exacerbations and remissions. After the acute period, symptoms of toxocariasis may be absent for a long time. In the chronic stage, even during the remission period, children continue to have subfebrile temperature, weakness, loss of appetite, sometimes weight loss, polyadenopathy, liver enlargement, and sometimes skin-allergic syndrome.

In some cases, toxocariasis is accompanied by myocarditis: the development of Löffler's endocarditis (fibroplastic parietal endocarditis with eosinophilia) has been described. There are reports of eosinophilic pancreatitis and the development of nephrotic syndrome. Larvae found in muscle tissue biopsies confirm that toxocariasis affects muscles. In tropical countries, pyogenic myositis is detected, apparently caused by toxocariasis.

One of the main and most constant manifestations of the visceral form of toxocariasis is persistent long-term eosinophilia of the blood, up to the development of eosinophilic-leukemoid reactions. The relative level of eosinophils, as a rule, exceeds 30%, and in some cases can reach 90%. The total number of leukocytes also increases to 15-20x10 ⁹ /l, and in some cases - up to 80x10 ⁹ /l. Eosinophilia can persist for months and even years. Moderate anemia is often observed in children. Increased ESR and hypergammaglobulinemia are characteristic. With liver damage, bilirubin and liver enzyme levels are elevated.

When toxocara larvae migrate to the brain, signs of CNS damage are detected (petit mal seizures, epileptiform attacks). In severe cases, meningoencephalitis, paresis, paralysis, and mental disorders are recorded.

Cases of disseminated toxocariasis with simultaneous damage to the liver, lungs and central nervous system in patients with immunodeficiency (during radiation therapy, treatment with corticosteroids, HIV infection, etc.) have been described.

Ocular toxocariasis

Ocular toxocariasis is more common in children and adolescents and is rarely combined with visceral lesions. Two types of lesions are observed - solitary granulomas and chronic endophthalmitis with exudation. Unilateral eye lesions with the development of chronic endophthalmitis, chorioretinitis, iridocyclitis, keratitis, papillitis, strabismus are characteristic. Retinal hemorrhages, optic nerve damage, eosinophilic abscesses of the ciliary body, panophthalmitis, retinal detachment are possible. Lesions by larvae of the paraorbital tissue are also observed, manifested by periodic edema. With severe edema, exophthalmos may develop. The number of eosinophils in the peripheral blood of patients with ocular toxocariasis is usually normal or slightly increased.

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Complications of toxocariasis

There may be a disruption of the functions of vital organs (brain, eyes, etc.). In some cases, the development of bronchial asthma is possible. Ocular toxocariasis is one of the possible causes of vision loss.

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Mortality and causes of death

Fatal outcomes from toxocariasis are rare, observed with massive invasion and associated with the migration of larvae into the myocardium and functionally important areas of the central nervous system.