Wild Mushroom Poisoning Syndromes

Poisoning syndromes with delayed onset:

Cytolytic (cell damaging) -

· Gyromitrin Syndrome (Monomethylhydrazine) - Frequently quite sudden onset of gastroenteritis (vomiting, with or without diarrhoea) is usually 6-8 hours after ingestion (but in extreme cases may occur earlier), sometimes accompanied by fever, severe headache, feeling of fullness and bloating, and abdominal pain with muscle cramps. The majority of cases do not progress past this stage and recovery usually occurs within a few days but some symptoms may continue for up to a week. In more serious cases of poisoning a second phase can develop after 36-48 hours, occasionally preceded by a brief period of relative well-being. This second phase is characterised by jaundice, sometimes with evidence of haemolysis, progressive liver failure, fever, and occasionally renal failure. In extreme cases there is a terminal phase progressing rapidly to coma, circulatory collapse, and respiratory arrest. Cases of this syndrome typically occur in the spring, reflecting the fruiting season of species from the Gyromitra and Morchella genera.

· Amatoxin Syndrome and other cyclopeptides - Onset of sudden “cholera-like” gastroenteritis (vomiting, watery diarrhoea, and colicky abdominal pain without fever) is usually 8-12hours (range 6-36 hours) after ingestion, which results in dehydration unless fluids are managed. This phase (8-48 hours) is followed by a period of apparent well being (48-72 hours) before commencement of terminal phase after a variable time with a return of abdominal symptoms, jaundice, evidence of acute hepatic toxicity which may rapidly result in liver failure, possible renal failure, convulsions and coma. Finally resulting in death after 7-10 days in 10-15% of patients.

· Orellanine Syndrome - Onset of gastroenteritis (nausea, vomiting, and anorexia) is at least 12 hours, after ingestion, often much longer (2-17 days), followed by increased urination, acute thirst, headache, coldness, shivering, lethargy, muscle and joint pain, and evidence of progressive kidney failure such as gradual decrease in urine output, sometimes finally ceasing altogether. In mild to moderate cases damage to kidneys may be reversible with only temporary, mild renal failure. Deaths are rare due to the general availability of renal dialysis, but renal transplantation and chronic dialysis may be required.

Haemolysins

  • Haemolytic Syndrome - Usually it is over 4 hours before symptoms appear. Poisoning by haemolytic compounds is characterized by the destruction of red blood cells which can lead to anaemia. Symptoms include pallor, and in exceptional cases kidney blockage. Haemolysins are thermo labile and the fungi containing these agents are only dangerous when eaten raw or undercooked.

Miscellaneous

· Ergotism Syndrome - Caused by consumption of ergot infected rye grain. Typically there is an incubation period in excess of 8 hours. Toxins affect the central nervous system causing convulsions and hallucinations. Another form of ergotism known as St Antony’s Fire develops when small amounts, usually as flour, are consumed over a long period causing burning and tingling sensations, particularly in fingers and toes. This is caused by the constriction of blood vessels which can lead to gangrene.

Poisonings with rapid onset:

· Coprine Syndrome - Symptoms, which can develop within 10 minutes after ingestion with, or after previous consumption of, alcohol. These can include a metallic taste, sensation of warmth, sweating, blushing and swelling of the face and neck, anxiety, vertigo, confusion, rapid heart rate, palpitations and chest pains, nausea, vomiting, diarrhoea, and sometimes collapse. Symptoms normally resolve in 2-3 hours depending on the quantity of alcohol consumed but can last up to 8 hours and will recur if alcohol is consumed again within 72 hours. The severity in each succeeding episode is usually diminishing.

· Muscarine Syndrome - Onset of symptoms is rapid and often within 15-30 minutes. Certainly within 1 hour almost all cases will manifest symptoms which vary depending on the quantity consumed, but can include sweating, flushing of the skin, increase salivation, excessive tear production, colicky abdominal pain, nausea, vomiting, diarrhoea, and blurred vision. A significant decrease in blood pressure is usually seen in severe poisonings. Occasionally cases include a painful urge to urinate and difficulty in breathing. Without administration of atropine, symptoms can persist for many hours depending on the amount consumed.

· Inebriation/Pantherine Syndrome - Caused by isoxazole derivatives including muscazone, muscimol & ibotenic acid. Symptoms almost always occur between 30 - 120 minutes after ingestion of fungus, although in unusual cases this can be delayed for up to 6 hours. These include nausea and vomiting (particularly in child cases), proceeded by a state of intoxication characterised by in-coordination, dizziness, confusion, delirium, and alteration between lethargy, euphoric, and manic behaviour. Patients can then fall into a deep ‘coma-like’ sleep. Hallucinations can occur as well as muscle cramps and spasms, and more rarely generalised seizures, particularly in children.

· Hallucinogenic Syndrome - Caused by indole compounds. Symptoms are noticeable within 30 minutes after ingestion and can include anxiety, tension, light headedness, mild abdominal pain, weakness, shivering, muscle aches, and sometimes a numbness of the lips. This is followed by a development of visual distortions, sense of euphoria and introspective state, inability to concentrate, depersonalisation, in-coordination, tremulous speech, and feelings of unreality. Physical features include dilated pupils, acuteness of hearing, facial flushing, confusion, vertigo, high body temperature, muscular weakness, and increased blood pressure, sweating, and tear production. Children may experience fever and occasionally seizures. Visual effects, distortion of perception, euphoria, and introspection can intensify and continue for approximately 2 hours followed by a gradual reduction in symptoms. In most cases a return to normality occurs within 4 - 8hrs, although headaches and fatigue may be experienced afterwards. ‘Flashbacks’ have been known to occur in some cases.

· Other Psychotropic Syndromes - Alkaloids. Some bracket fungi, such as Meripilus giganteus and Laetiporus sulphureus are known to contain unidentified toxins. Susceptibility to this type of poisoning is extremely variable between individuals. L. sulphureus is known to contain hordenine, N-methyltyramine, and tyramine. These alkaloids are known to cause nausea and vomiting in some, but not all, cases. These compounds could be responsible for central nervous system manifestations such as dizziness, and disorientation in others.

· Gastrointestinal Syndrome - included within this syndrome is an array of fungi, all of which have some features in common. They provoke symptoms in many, but not all people. They all affect the gastrointestinal tract with various combinations of nausea, vomiting, colicky abdominal pain, and diarrhoea. The toxins are largely unknown. The majority produce symptoms between 15 minutes and 2 hours after ingestion. Two species, Entoloma sinuatum and Paxillus involutus, have been known to cause fatalities and Hypholoma fasciculare in some cases has been known to cause liver damage. However most other cases with symptoms lasting 30 minutes to 2 hours require no treatment. Complications can occur in cases where more than one species is consumed at the same time.

· Allergic Reactions - toxic symptoms are exhibited in some individuals and not others. There is typically an early onset of symptoms including ‘nettle-rash’ on skin, headaches, and gastroenteritis. Reactions can be quite violent if large quantities are consumed. Cultivated mushrooms and common wild mushrooms such as Cantharellus cibarius can cause allergic reactions in the same way that many other foods can. Species to which some people are known to react include Clitocybe nebularis, Lepista nuda (particularly if not well cooked), and Chlorophyllum rhacodes. Fungal spores can also cause allergic reactions as well as being irritants to eyes and can cause dermatitis.

· Contamination - Poisoning can be caused by contamination of mushrooms by herbicides and pesticides, as well as chemicals from contaminated sites such as farm yards and building sites. Road dust and traffic fumes may contain lead and mercury. Fungi readily absorb heavy metals and are susceptible to contamination from radioactive fall-out.

· Decomposition - Contamination by microscopic fungi and bacterial infection can occur in decaying mushrooms. This type of food poisoning can be caused by collecting old or partly rotten specimens, collecting in plastic bags or closed containers, or through spoilage by incorrect long term storage. Symptoms are usually gastro-enteric and of short duration.

· Imaginary poisoning - Fear of fungal poisoning is widespread. Fear alone can cause some individuals to experience symptoms such as stomach ache, nausea, and diarrhoea. Panic attacks can induce cold sweats, flushing, dizziness, and light headedness which could be confused with muscarine poisoning, however in this type of case there would be an increase in blood pressure, which is not manifested in the latter syndrome. Panic is not only limited to the potential victim. Parents and others in a position of responsibility, including medical practitioners, can also be susceptible which may lead to a panic response.

This summary of mushroom poisoning syndromes follows:

Benjamin, D. (1995), Mushrooms: poisons and panaceas. W.H. Freeman and Company

but information is also drawn from:

Oldridge, S.G., Pegler,D.N. & Spooner, B.M. (1989) Wild Mushroom and Toadstool Poisoning. RBGK

Pegler, D.N. & Watling, R (1982) British Toxic Fungi. Bulletin of The British Mycological Society V16, P1

Watling, R (1995) Children and Toxic Fungi. RBGE

The accompanying poisoning syndrome diagnosis flow chart is drawn from the same sources.

This is not intended as an exhaustive list of all toxic fungi in the United Kingdom and there are several excluded species for which the toxicology is not yet fully understood.

Neville Kilkenny April 2010