Viral Encephalitis Masquerading as a Fulminant Anticholinergic Toxidrome

Case Report: Emergency physicians are well versed in the recognition and management of certain poisonings which present with characteristic toxidromes. We present a case of a young pharmacy student who presented with altered mental status, tachycardia, facial flushing, dilated pupils, and dry skin and mucous membranes presumably due to anticholinergic poisoning. She improved with a combination of benzodiazepines and the acetylcholinesterase inhibitor physostigmine. However, following resolution of her initial symptoms, she became ill again and the subsequent neurologic evaluation revealed a diencephalic lesion consistent with a viral encephalitis. The acute anticholinergic signs and symptoms resulted from this lesion in an area of large cholinergic outflow. Although recognition and management of her acute anticholinergic findings were appropriate, they were not the manifestations of an acute anticholinergic ingestion.