Neuroangiostrongyliasis presenting as abdominal allodynia mimicking hepatobiliary disease in urban Australia

Introduction: - Angiostrongylus cantonensis is a neurotropic helminth and the leading cause of eosinophilic meningitis in humans worldwide. Infection usually follows ingestion of larvae in contaminated produce or intermediate hosts. Case description:-A patient in their 70s from urban Sydney, New South Wales presented to an Emergency Department four times in 10 days with right upper quadrant pain and bilateral lower limb pain. Abdominal ultrasound showed cholelithiasis, but inflammatory markers remained unremarkable and further abdominal investigations were non-diagnostic. Focal allodynia and fluctuating peripheral eosinophilia were present early. The patient subsequently developed severe headache, confusion and meningism. MRI demonstrated leptomeningeal enhancement and repeat cerebrospinal fluid analysis confirmed eosinophilic meningitis. Exposure history identified gardening and frequent consumption of home-grown leafy greens. CSF PCR and serology confirmed locally acquired Angiostrongylus cantonensis. The patient’s allodynia improved after a short course of prednisolone, while neurocognitive function recovered gradually over 12 months. Discussion:- This case highlights that atypical abdominal pain with focal allodynia and peripheral eosinophilia, in regions where A. cantonensis is established, should prompt early consideration of neuroangiostrongyliasis. History should assess gardening activity, snail and slug contact, and the ingestion of raw leafy greens.