Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 21 3 2026 09 02 414 419 Setareh Askari Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Eshrat Beigom Kia Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Enayat Darabi Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Zohreh Fakhrieh Kashan Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran 2026 06 01 2026 09 02 Toxocariasis is a globally distributed zoonotic helminthic infection caused by Toxocara species. Humans are accidental hosts in whom the larvae cannot complete their life cycle; instead, they migrate through various tissues, resulting in a broad spectrum of clinical manifestations. We report the case of a 4-year-old boy from western Iran with a history of close contact with cats and dogs who presented with per orbital edema and swelling of the hands and feet. He was referred to the Diagnostic Laboratory of Helminths, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran in March 2024. Laboratory investigations revealed marked hypereosinophilia, raising suspicion of a parasitic etiology. Serological testing was positive for toxocariasis, while computed tomography (CT) revealed subtle hepatic abnormalities. The patient's clinical manifestations improved following concomitant treatment with albendazole and prednisolone, and the eosinophil count returned to the normal range during follow-up. This case highlights the importance of considering toxocariasis in children presenting with edema, marked hypereosinophilia, and a history of close contact with cats or dogs. However, although the patient was serologically positive for toxocariasis, not all clinical manifestations could be definitively attributed to the infection. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/4943 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/4943/1517