The California Department of Public Health (CDPH) has issued an urgent advisory following a recent outbreak of amatoxin poisoning linked to the consumption of wild, foraged mushrooms.

As of Dec. 5, 21 cases have been identified by the California Poison Control System (CPCS) with significant clusters reported in the Monterey and San Francisco bay areas, although the risk is statewide, CDPH warns.

Toxic mushrooms, such as the death cap (Amanita phalloides), cannot be distinguished by taste from varieties that are safe to consume, the Health Department said.

Death cap mushrooms are found in many parts of California, particularly near oaks and other hardwood trees, including pine trees. Consuming these mushrooms can lead to severe poisoning for humans and animals. Cooking, boiling, drying, or freezing these mushrooms does not make them safe to eat.

“Severe, potentially fatal liver damage is associated with the consumption of foraged wild mushrooms,” said Dr. Henning Ansorg, Santa Barbara County Public Health officer. “So we are urging residents to be cautious when purchasing wild mushrooms from street vendors, and to avoid consuming food prepared with foraged wild mushrooms during this high-risk season.”

Symptoms of amatoxin poisoning include watery diarrhea, nausea, vomiting, abdominal pain, and dehydration within six to 24 hours of ingestion.

“Call 911 if severe symptoms develop, like violent vomiting, bloody diarrhea, and severe abdominal cramps,” the Health Department said.

Given the grave risk posed by consuming these toxic mushrooms, County Health officials remind residents that the best way to stay safe is to not eat wild mushrooms.

If you or someone you know has eaten a poisonous mushroom, seek immediate medical care, or call the California Poison Control Hotline, 1-800-222-1222. The hotline can tell you exactly what to do in case of a mushroom poisoning. It can also provide guidance to medical providers to ensure proper care.

If a pet eats a poisonous mushroom, contact your veterinarian or the American SPCA Animal Poison Control Center, 1-888-426-4435.

For more information, visit the CDPH website.