Ingestion of Amanita phalloides is responsible for a majority of mushroom-related deaths worldwide. Amatoxins, the principal toxic alkaloids found in these fungi, cause cell injury by halting protein synthesis. A possible antidote licensed in most of Europe, intravenous silibinin, is undergoing evaluation by clinical trial in the United States.

In December 2016, 14 cases of Amanita phalloides poisoning were identified by the California Poison Control System (CPCS) among persons who had consumed foraged wild mushrooms. In the past few years before this outbreak, CPCS only received reports of a few mushroom poisoning cases per year. All patients in this outbreak had gastrointestinal manifestations of intoxication leading to dehydration and hepatotoxicity. Three patients received liver transplants; all patients recovered, although one (a child) had permanent neurologic impairment.

Wild-picked mushrooms should be evaluated by a trained mycologist before ingestion. Inexperienced foragers should be strongly discouraged from eating any wild mushrooms. Health care providers should be aware of the potential for toxicity after wild mushroom ingestion, that gastrointestinal symptoms mimicking viral gastroenteritis can occur after ingestion and slowly progress to potentially fatal hepatotoxicity, and should contact the local poison center for reporting and assistance with management of these patients.

Amanita phalloides Mushroom Poisonings- Northern California, December 2016

MMWR, Weekly, June 2, 2017, 66(21); 549-553, Kathy T. Vo, MD; Martha E. Montgomery, MD; S. Todd Mitchell, MD; Pieter H. Scheerlinck, MD; Daniel K. Colby, MD; Kathryn H. Meier, PharmD; Susan Kim-Katz, PharmD; Ilene B. Anderson, PharmD; Steven R. Offerman, MD; Kent R. Olson, MD; Craig G. Smollin, MD

https://www.cdc.gov/mmwr/volumes/66/wr/mm6621a1.htm?s_cid=mm6621a1_e