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Mushroom poisoning

In addition to edible mushroom species, in the woods also grow non-edible, toxic, poisonous and deadly poisonous mushrooms. Every year in Italy about 40,000 cases of mushroom poisoning are recorded and at least a dozen deaths.

The forms of poisoning caused by intake of mushrooms can be of varied nature depending on the fungal species consumed, with highly variable clinical pictures. The poisonings caused by potentially fatal mushrooms cause irreversible organ damages to the liver, in the case of fungi belonging to the genus Amanita and Lepiota, and to kidneys in the case of the genus Cortinarius. Moreover, there are countless other toxic species that, while not jeopardizing the patient's life, are still responsible for poisonings whose symptoms may involve the gastrointestinal tract up to complications of the central nervous system. It is not uncommon the case in which mushrooms defined as edible lead poisonings if the necessary precautions in preparation and cooking have not been observed.

The only way to determine the edibility of a mushroom is to determine the species. The empirical methods have no scientific basis, it should be clarified definitively that the commonplaces such tests with garlic, silver coins, parsley, etc. are to be discredited because they have absolutely no validity. Mixing them with the food of domestic animals, besides being criminal, is useless because the response to exposure to toxins may be different than that in humans and in the case of fungi of the genus Cortinarius, symptoms may appear several days after consumption (up to 20), well above the normal waiting time for a suspected symptoms appearance.

The Mycologist is the institutional figure, serving in the Mycological Inspectorates set up at the Local Health Authorities (ASL), responsible for the recognition of fungal species in order to determine their edibility. The recognition of a mushroom requires such a botanical knowledge that only a mycologist have.

The collectors are invited to submit their harvest to a preventive visit rather than venturing into a reckless consumption of non-controlled mushrooms. The mushrooms visit is a completely FREE service, after which an official certificate is issued which lists the scientific names of the species identified, attests their edibility and provides the proper instructions for the consumption. Do not rely on improvised experts or on the determination made solely through the descriptions and/or images of texts, because the pictures can escape the fundamental characteristics for classifications.

Recommendations for the collection

  • Do not pick all the mushrooms found indiscriminately, not to destroy the ecosystem balance.
  • Mushrooms should be collected in whole, not cut, since essential parts for the identification of species may remain in the soil.
  • Do not resort to the use of spades, hoes, hooks, and various tools that may damage the humus layer of the brushwood.
  • The mushrooms should be collected healthy and not if in a bad state: moldy, masked, putrid, and anyway altered.
  • Specimens not collected must be left as they are and not destroyed, kicked or beaten.
  • The mushrooms must be transported in rigid and aerated containers (eg. Wicker baskets) that allow the further dissemination of the spores. Moreover, this way phenomena of compression and fermentation of fungi can be avoided. Do not put the good mushrooms together with the suspected mushrooms: some fragments of poisonous mushrooms can be harnessed in the edible ones, this might be enough to cause problems.
  • Do not collect mushrooms grown in suspicious areas, eg. near landfills, piles of rubble, banks of filthy rivers, public parks and gardens, close to airports, close to highways or roads with heavy vehicular traffic, industrial plants, incinerators, burial sites, power stations, orchards and/or crops treated with phytosanitary products.
  • Do not give mushrooms to other people if their edibility is uncertain, because you incur heavy responsibilities.

Recommendations for the consumption

  • The cooking, drying or other treatments cannot make deadly mushrooms edible; poisonous mushrooms contain heat-stable toxins that retain their toxic properties anyway.
  • All the edible mushrooms should be eaten well cooked: the raw ones are poorly digestible, if not poisonous.
  • The common Armillaria mellea is toxic if raw and must necessarily be pre-boiled for at least 15 minutes before the next cooking.
  • If you intend to keep Armillaria mellea by freezing them remember that the treatment of pre-boiling must be performed prior to freezing.
  • If you do not perform it, toxins exposed to low temperatures change over from heat-labile to heat-stable so that all the heat treatments after freezing are completely ineffective for the deactivation of toxins.
  • Do not let children, pregnant or nursing women, old people, people who have intolerance to certain foods or medicines or suffering from gastric, liver, pancreas, kidney disorders, eat mushrooms without the consent of the doctor.
  • Mushrooms are hard to digest: even healthy adults should eat in moderation.
  • The mushrooms considered edible should be kept in a rigid aired container and in a cool place. Their shelf life is extremely low so that consumption, or any maintenance operations, must be carried out as soon as possible, preceded by a thorough cleaning by repeated washings and a proper cooking for at least 30 minutes.

Recommendations for the purchase

  • Never buy mushrooms offered by unauthorized sellers.
  • In retail outlets, check the box or container to be with the required "label" reporting that the mycological check has been carried out by the Mycological Inspectors of the Local Health Authorities (ASL) reporting the scientific name of the species.
  • If there is no control label, you should not buy the product and report the incident to the bodies responsible for food control (Technical prevention of ASL, NAS, etc...).

Mushrooms poisoning
The onset of mushrooms poisoning almost always originates with gastrointestinal manifestations, but some mushrooms lead to more or less serious and potentially lethal diseases if they include organ damages such as liver and kidneys.
The severity of poisoning depends on the species and the amount of mushrooms ingested.

  • Gastrointestinal syndrome: the most poisonous mushrooms are responsible for this syndrome. Symptoms usually begin after 1-3 hours from the ingestion and consist of vomiting, abdominal cramps and diarrhea. The treatment includes gastric lavage, fluid and lost electrolytes reintegration.
  • Phalloides syndrome: begins after 8 to 12 hours with abdominal cramps, vomiting and profuse diarrhea. There is no effective therapy: in 24 - 48 hours you experience serious and sometimes fatal liver damages. The possibility of liver transplantation is considered. Gastric lavage, intestinal washing, forced diuresis are required, charcoal and plasma substitutes are administered.
  • Orellanine syndrome: the long latency of symptoms that may occur beyond 15 days after ingestion, makes it difficult to relate the cause to the consumption of mushrooms, causes irreversible kidney damages and is often fatal. If a kidney transplant is not possible, it is necessary to use dialysis for life.
  • Anticholinergic syndrome: symptoms, of neurological type, start after a few hours with agitation, convulsions, mydriasis, coma, sometimes enteric disorders.
  • Muscarine syndrome: is characterized by intense salivation, incessant lacrimation, accompanied by nausea, vomiting, abdominal cramps, diarrhea, breathing difficulties to a real asthmatic crisis, decreased heart rate, hypotension, headache and decreased pupil size (miosis).

If, after eating mushrooms, disorders arise, we recommend:

  • go immediately to the nearest Emergency Room or hospital;
  • make available and bring the leftovers of the meal, even if cooked, and all the mushrooms still available, including those thrown into the dustbin;
  • don't try any autonomous treatment.


[Source: ASL of Milan – Lombardy Regional Authority]

In-depth sections:
Web site of ASL 5 of Pisa (mycological service) – In Italian