Management overview for Amanita phalloides mushroom poisoning

Mushrooms that contain cyclopeptides cause the majority of deaths from mushroom poisoning. The most serious poisonings are caused by Amanita phalloides mushrooms that contain amatoxin and can cause fulminant liver failure and death if eaten. Many other mushrooms that contain smaller amounts of cyclopeptides also grow in Australia (eg Galerina marginata or Lepiota species). In Australia, most cases of cyclopeptide mushroom poisoning have been in the Australian Capital Territory, with isolated cases in Victoria and South Australia.

Most deaths in Australia result from adults eating poisonous foraged mushrooms that they have mistaken for edible mushrooms from their countries of origin (eg Amanita phalloides mushrooms resemble straw mushrooms). Foragers may collect and ingest several types of mushrooms, which can confuse the clinical presentation. Cooking Amanita phalloides mushrooms does not inactivate the amatoxin as the toxin is heat stable.

Most mushroom ingestions by children are small exploratory amounts and are generally benign. However, one Amanita phalloides mushroom cap ingested by a child can be more toxic than in an adult, because the dose of amatoxin per kilogram of body weight is higher.

If Amanita phalloides poisoning is suspected, urgently contact a clinical toxicologist or poisons information centre (13 11 26). If a sample of the ingested mushroom is available, send a set of photographs (taken from various angles) to the poisons information centre for assistance with identification. Mycological expertise is needed to identify the mushroom species, especially because morphology can vary during the life cycle of the mushroom.

Management of Amanita phalloides poisoning is primarily supportive care and treatment is aimed at minimising liver injury and preventing liver failure. Gastrointestinal decontamination and enhanced elimination with activated charcoal are important management considerations.