Snapshot A 5-year-old boy presents to his pediatrician due to abdominal pain and a seizure. He has been complaining of abdominal pain and discomfort for approximately 10 days, which his parents attribute it to stress. The parents deny any recent travel or sick contacts for the patient. He recently got a puppy about 1 month ago. Physical examination is remarkable for pain upon neck flexion and hepatomegaly. A complete blood cell count is notable for prominent eosinophilia. Introduction Definition human infection caused by the Toxocara nematode Microbiology caused by Toxocara canis (in dogs) and Toxocara cati (in cats) roundworm nematodes Associated conditions seizures myocarditis visual impairment and blindness Epidemiology Incidence more common in tropical regions and rural populations of the world visceral larva migrans most commonly affects children Risk factors contact with dogs or cats exposure to infected eggs in soil vegetables and fruits encapsulated larvae exposure in undercooked meats (e.g., rabbit, chicken, cattle, and swine) ETIOLOGY Pathophysiology the adult nematode lives in the upper gastrointestinal tract of a dog or cat → the female nematode produces eggs that get excreted in feces → the excreted eggs become embryonated → ingestion of embryonated eggs lead to hatching of these eggs in the small intestines of the host → the larvae perforate the intestinal wall and enter the circulatory system can migrate to the brain, causing neurotoxocariasis can migrate to the lung and liver, causing visceral larva migrans can migrate to the eye, causing ocular larva migrans the fetus can also be infected transplacentally or through the breast milk in pregnant women Presentation Visceral larva migrans symptoms fever abdominal pain decreased appetite chronic nonproductive cough dyspnea lymphadenopathy physical exam wheezes hepatomegaly or nodularity Ocular larva migrans symptoms visual impairment physical exam poor visual acuity and strabismus may be present uveitis retinal granulomatous lesions on fundoscopy Studies Labs eosinophilia Serology enzyme-linked immunosorbent assay (ELISA) with larval antigens Differential Schistosomiasis differentiating factors no apparent signs of liver dysfunction Treatment Medical albendazole indication treatment of choice since the drug effectively distributes throughout the body (including the eyes and brain) Complications Blindness Neurodegenerative disorders (e.g., seizures and dementia)