• Counsel patients, caregivers, and guardians not to forage wild mushrooms.
• Counsel patients, caregivers, and guardians to avoid consuming food prepared with foraged wild mushrooms.
• Any patient who presents with recent or active gastrointestinal symptoms after consumption of death cap mushrooms or unknown foraged wild mushrooms warrants careful evaluation for amatoxin poisoning and consideration for hospital admission.
• Initial symptoms (typically 6-24 hours post-ingestion) include profuse, watery diarrhea as well as other GI complaints such as nausea, vomiting, or abdominal pain. Fluid loss may lead to hypovolemia, acute kidney failure, circulatory shock, and death. Patients often experience a gradual resolution of GI symptoms within 24 hours of onset, which falsely suggests toxicity has resolved – elevations in liver enzymes are typically seen within 24 to 36 hours after ingestion. 
• Severely poisoned patients may develop irreversible hepatic failure within 48 to 96 hours after ingestion, which may be accompanied by acute kidney failure or pancreatitis. After stabilization and initiation of specific therapy, patients with signs of rapidly progressing acute liver injury or acute liver failure may warrant transfer to a liver transplant center.
• Ask patients presenting with symptoms consistent with mushroom toxicity about mushroom consumption. 
• Collect and record information about when and where the mushrooms were collected, sourced, or purchased, and if they have any remaining mushrooms which could be identified or analyzed.
• Obtain early consultation with a medical toxicologist with expertise in managing patients with mushroom poisoning. Contact CPCS (1-800-222-1222) to report cases of illness after consumption of amatoxin-containing mushrooms and/or for advice on medical management of these patients.
• Emergency and supportive measures: 
• Proper supportive care measures in an emergency room or hospital setting can reduce mortality. These measures include fluid resuscitation for hypovolemic shock, correction of electrolyte disturbances associated with fluid losses, elimination enhancement with multiple dose activated charcoal, and supportive care related to liver dysfunction. Gastric emptying by gastric lavage or ipecac is not recommended and should not be performed. Due to rapid absorption of amatoxin hours before symptom onset, lavage has little to no benefit that outweighs the risk of the procedure. 
• Reduction of amatoxin uptake by hepatocytes is possible, though experimental. IV silbinin dihemisuccinate (Legalon SIL) is the preferred treatment and appears to be most effective within 24 hours of mushroom ingestion, but may be obtained only by application for an Emergency Investigational New Drug to the US Food and Drug Administration (FDA) Expanded Access Program. Other treatments, including high doses of IV penicillin G, may work to reduce amatoxin uptake. 
• To request Legalon, contact the manufacturer using Emergency_Legalon@marken.com (email preferred, can also call calling customer service at 484-754-7500). Treating clinicians will also need to call FDA Emergency Call Center at 866-300-4374 or 301-796-8240.
• Antioxidant therapy: Antioxidants, such as IV acetylcysteine, have been used historically in the treatment of amatoxin-containing mushroom poisonings in which there is evidence of hepatotoxicity. 
• Liver failure therapies: transfer to a tertiary care center capable of performing liver transplantation or other bridging liver failure therapies (e.g., MARS, fractionated plasma separation and adsorption system) should occur if clinical signs of hepatic injury are moderate to severe.
• Testing: As appropriate, clinical diagnosis should be confirmed by amatoxin detection in the urine or mushroom identification. CDPH and CPCS can assist with laboratory analyses of patient urine samples or mushroom specimens – contact the CDPH Laboratory Response Network’s CT Training and Outreach Coordinator, Terri Jackson at (530) 304-7439 or Terri.Jackson@cdph.ca.gov.
  

Recommendations for Public Health Professionals

• Advise residents not to forage wild mushrooms and to be cautious when purchasing wild mushrooms from street vendors and farmers markets. Advise residents to avoid consuming food prepared with foraged wild mushrooms
• Familiarize yourself with the risk level in your communities. Regional and local mycological societies may be useful resources. Death cap mushrooms have been found in many parts of California, particularly in Central and Northern California counties.
• Work with local partners to minimize exposure. Consider outreach to foraging groups, coordination with veterinarians and animal health services, as well as coordination with parks departments to post advisories in public spaces where these mushrooms may be found.

​Resourc​​es 

Peredy, T.R. Amatoxin-containing mushroom poisoning (eg, Amanita phalloides): Clinical manifestations, diagnosis, and treatment. In: UpToDate. Last updated March 25, 2024. Accessed December 2, 2025. https://www.uptodate.com/contents/amatoxin-containing-mushroom-poisoning-eg-amanita-phalloides-clinical-manifestations-diagnosis-and-treatment 

Horowitz, B.Z. et al. Mushroom Toxicity. In: Medscape: Tools & Reference: Emergency Medicine. Last updated November 11, 2025. Accessed December 3, 2025. https://emedicine.medscape.com/article/1008902-overview

Amanita phalloides Mushroom Poisonings — Northern California, December 2016. Vo, K.T. MMWR Morb Mortal Wkly Rep 2017; 66:549-553. 

Monterey County. 2025. Health Advisory: Severe Hepatotoxicity Following Consumption of Wild Mushrooms. December 1, 2025. Accessed December 2, 2025. https://www.countyofmonterey.gov/Home/Components/News/News/11687/

CDPH. 2016. Use Caution When Collecting, Eating Wild Mushrooms. Press Release. Last updated March 22, 2017. Accessed December 2, 2025. https://www.cdph.ca.gov/Programs/OPA/Pages/NR16-077.aspx ​