Pulmonary presentation of Toxocara sp. infection in children.

Introduction: The aim of this study was to investigate the associations between radiological findings, blood eosinophilia, hyperimmunoglobulinemia E and G and Toxocara seropositivity in Polish children with newly diagnosed pulmonary infiltration.

Material and methods: We retrospectively analyzed the documentation of 119 patients, aged 1 to 18 years (mean age: 7.21 ± 4.82), who were seropositive in Toxocara sp. antibodies. In all cases, peripheral blood eosinophils and leukocyte counts, serum total IgE, IgG levels and specific IgG antibodies against excretory and secretory Toxocara sp. antigens were measured at the first presentation. After the confirmation of seropositivity, all children had a routine radiological examination.

Results: In the documentation of 23 children (mean age 3.58 ± 2.63 years) we found abnormalities in the radiological examination of their lungs. Fifteen children who had abnormalities in radiological findings presented clinical respiratory complaints such as chronic cough, wheezing, asthma and haemoptysis. Eight children were asymptomatic. The analysis of peripheral eosinophils and leukocyte number, the level of IgE and specific anti-Toxocara IgG presented significantly higher values in children with radiological lesions than in children who had correct radiology. The concentrations of total IgG and gamma globulins were not significantly different. In 10 patients CT showed irregular round nodules with and without halo ranging from 1 to 13 mm. The number of nodules varied from a single lesion to multiple, disseminated ones. All nodules were located in peripheral areas of the lungs. None of them were found in the central areas. In 13 patients, CT images showed ground-glass opacities with ill-defined margins. None of the CT images presented lymphadenopathy and pleural effusion.

Conclusion: The pulmonary lesions in small children with high eosinophilia and hyperimmunoglobulinemia E could be related to toxocariasis and for this reason they are eligible to undergo therapy with prolonged observation for several months, rather than start invasive malignancy investigations.