Mushroom poisoning

Eating poisonous mushrooms can make a person very ill or even have life-threatening consequences.

You can't tell if a mushroom is toxic by its taste and there is no simple reliable test that shows which mushrooms are safe to eat. Even mushroom experts can have difficulty identifying some species. The appearance of a type of mushroom changes depending on their stage of growth, so poisonous mushrooms can look very similar and be easily mistaken for edible supermarket varieties.

Mushroom poisoning emergencies

In an emergency, always call Triple Zero (000) for an ambulance.

• Anyone who becomes ill after eating a wild mushroom should seek urgent medical attention by going to the nearest emergency department or medical clinic.
• If you suspect a person has eaten a wild mushroom, contact the Poisons Information Centre on 13 11 26 and they will advise if it is necessary to seek immediate medical attention.
• Do not induce vomiting or give the person anything to drink unless advised by the Poisons Information Centre or another medical professional.
• If possible, take a sample of the mushroom or a photo to help identify the species of mushroom.

Symptoms of mushroom poisoning

Symptoms can be delayed by 6 to 24 hours after eating poisonous mushrooms. Severity depends on how much is eaten and symptoms may last for 2 to 3 days. Symptoms may include:

• violent stomach cramps
• abdominal pain
• nausea
• vomiting
• diarrhoea.

Who is most at risk?

Anyone who has consumed a wild mushroom is at risk of potential life-threatening illness.

• Young children - at this age, it is a natural behaviour for toddlers to put things in their mouths and eat plant matter. Most young children who eat poisonous mushrooms find them in the garden at home.
• Cooking enthusiasts - foraging for wild food is becoming increasingly popular in Australia and may be promoted by culinary experts in the media and on television cooking programs. But when people gather wild mushrooms, they can accidentally include toxic species which can easily be mistaken for “edible” mushrooms.
• Overseas visitors from countries in the Northern Hemisphere - where gathering mushrooms is an established cultural activity.
• Pets - there have been a number of cases reported of dogs that have been poisoned and died from acute liver failure after eating poisonous mushrooms in backyards and when out on walks. While cats tend to be more discerning about what they eat they are still at risk - particularly inquisitive kittens that might chew on a toxic species.

Preventing poisoning from wild mushrooms

Things you can do to prevent poisoning from wild mushrooms:

• Do not pick and eat wild mushrooms.
• Only eat mushrooms that have been purchased from a reliable greengrocer or supermarket.
• Do not cook, peel, soak or dry wild mushrooms as this does not remove or inactivate any poison to make them safe to eat.
• Keep a close eye on young children and pets outdoors when mushrooms are most likely to be growing.
• Talk to your families, friends and neighbours about the dangers of wild mushrooms.

Types of poisonous mushrooms

There are a number of poisonous mushrooms that have been identified in Australia, however not all of these have been found to grow in Queensland. For example, Death Cap mushrooms (Amanita phalloides) are one of the most deadly mushrooms in the world, responsible for around 90% of all mushroom poisoning deaths. They have been found in the Australian Capital Territory, Victoria, Tasmania and South Australia.

The mushrooms identified below include the poisonous mushrooms that are the most common in Queensland.

Warning: seek urgent medical attention for any ingestion of any of the following mushrooms.

Green-spored parasol (Chlorophyllum molybdites)

• Extremely toxic, has been known to cause injury, permanent disability, and in some cases, death. Removal and disposal of existing plants is strongly recommended.
• Very common in lawns and garden beds, during wet periods of spring, summer and autumn, occurring in groups or fairy rings.
• This species is easily mistaken for ‘edible’ mushrooms and they have a strong mushroom smell and taste.
• The large caps, 10-30cm in diameter, are whitish to brown, broadly conical often with margins slightly upturned, and covered with concentric circles of pinkish-brown to chocolate-brown scales. The centre of the cap is entirely brown. The gills are free from the stem, white at first, becoming greenish when the spores mature. The base of the stem is slightly swollen whilst a prominent and movable white or brownish ring with a fringed margin is present on the stem closer to the cap. The most obvious feature is the greenish gills of mature caps.

Symptoms from eating green-spored parasol

Symptoms are particularly severe when the mushroom is consumed raw. Symptoms usually begin within 30 minutes to two hours and include drowsiness, severe vomiting and diarrhoea, sometimes with bleeding from the gut and significant fluid and electrolyte loss. Blue discolouration of lips, tongue and fingernails may occur. Fatalities in young children have been reported.

Yellow-staining mushrooms (Agaricus xanthodermus)

• Potentially toxic, depending on the level of exposure.
• In urban areas the Yellow-staining Mushroom is much more common than edible mushrooms. It can grow in clusters or large troops in lawns among grass, or in garden beds among leaf litter. It is found mostly in urban areas, sometimes in bushland, but usually in disturbed areas such as around picnic areas or where the land has been cleared. They usually appear after heavy rain in late summer and autumn but can occur throughout the year.
• The slender stem is white or yellowish, swollen and often hollow at the base, and usually with a membranous white or yellowish ring at the top. Cutting through the stem elicits an immediate vivid chrome yellow reaction. The odour is strong (phenolic), unpleasant, similar to iodine or kerosene, and is more intense upon cooking.
• Their appearance is very similar to edible mushrooms.

Symptoms from eating Yellow-staining mushrooms

Symptoms can begin immediately or up to two hours after the meal, and may include intense nausea, vomiting, diarrhoea, and abdominal pains.

Earth balls (Scleroderma)

• Earth balls information is available from Children's Health Queensland Hospital and Health Service (HHS).
• Potentially toxic, depending on the level of exposure.
• Common in Queensland.
• Roughly ball-shaped, often looking somewhat like a scaly or warty potato, 2–10+ cm in diameter, brownish and usually lacking a stem. The surface is thin to thick and a variation of light yellow, yellowish-brown to brown; smooth to sectioned into discrete plates or scales by cracks or fissures. The interior is at first white to off-white, becoming violet to violet-black with white veins just prior to maturity. Once spores are fully mature the interior is filled with an olive-brown to brown, powder. The earth-ball may crack open at the top or split radially to release the spores.

Symptoms from eating Earth balls

• These mushrooms may be gastro-intestinal irritants, causing abdominal pain, vomiting and diarrhoea. Onset may be 15 minutes to two hours after eating, and symptoms subside in 3-4 hours. Full recovery may take several days.

Haymaker’s mushroom (Panaeolina foenisecii)

• Haymaker's mushroom information is available from Children's Health Queensland HHS
• Potentially toxic, depending on the level of exposure.
• This small brown-capped fungus occurs in small groups, commonly in lawns. The cap is hemispherical, to convex, 2–4cm diameter, dry (not slimy) and light to dark brown. The gills are greyish becoming dark brown and are attached to the stem. The stem is tough, cylindrical and light brown.

Symptoms from eating Haymaker's mushroom

• This mushroom may cause hallucinations in children, but the toxin is not known.

More information

For more information on poisonous mushrooms, visit the Children’s Health Queensland HHS's Plants and mushrooms (fungi) poisonous to people or contact the Poisons Information Centre.