Hyperactivity and Euphoria Without Agitation Due to Hyoscyamus niger (Henbane) Poisoning in a Child.

Hyoscyamus niger (henbane) is a toxic plant containing tropane alkaloids that can cause anticholinergic toxicity. Pediatric presentations may differ from adults and may include atypical behavioral manifestations such as hyperactivity and euphoria without agitation. An 11-year-old previously healthy boy presented with sudden behavioral changes, hyperactivity, and unexplained euphoria. Approximately four hours earlier, he had ingested about one tablespoon of fresh Hyoscyamus niger seeds. Physical examination revealed minimal mydriasis and mild flushing. The patient was cooperative but disoriented, with visual hallucinations. Laboratory tests were normal, and electrocardiography showed sinus tachycardia. Findings were consistent with anticholinergic toxicity. Activated charcoal and physostigmine were not administered due to delayed presentation and absence of severe or life-threatening symptoms. Symptoms resolved completely within 24 hours with supportive care. In conclusion, Hyoscyamus niger intoxication may present predominantly with hyperactivity and euphoria without agitation, representing an atypical behavioral phenotype in pediatric patients. Plant-derived toxicities should be considered when acute behavioral changes occur, especially in rural settings.