Post on 08-May-2015
description
“What is edible & what is not?”A glance at Mushroom Poisoning
Dr. Shatdal Chaudhary MDAssistant Professor
Department of Internal MedicineB.P. Koirala Institute of Health Sciences, Dharan
shatdalchaudhary@yahoo.com
• Historical aspects
• Magnitude of problem
• How are Mushroom Poisonings classified clinically?
• What is the specific management strategy for each group?
• Identification of mushroom species & “What is edible & what is not?”
Outline
Mesoamerican History :
• Over 400 religious mushroom stones have been found in Mayan excavations.
Roman History :
• Claudius (AD 54) marries his niece Agrippina who serves him Amanita Phaloides, Nero ascends to the throne.*
*De Impertoribus Romanis An Online Encyclopedia of Roman Emperor
Roman History:
• Pope Clement VII excommunicates Henry VIII.
• Pope was fed Amanita Phaloides and died
Russian History :
• The Siberians of the 14-15th Century collected Amanita Muscaria as the intoxicant of choice until Vodka was invented in the 16th Century.
• Tsar Alexis and his wife (parents of Peter the Great) ate Amanita Phalloides and died on January 25, 1694. Peter ascended to the throne and changed the course of history.
Chinese History :
• The Chinese have used Ganoderma species (polypore mushroom) for food and medicine for 5000 years
Magnitude of problem
• Accidental mushroom poisoning are constantly seen all over world.
• American Association of Poison Control Centers = 10000 cases/year
• Incidence: In USA 5 /100,000 population per year.
• Even in USA 95% cases exact species were unidentified.
• Amanita and Boletus species were responsible for fatality
• Although over 5000 varieties of mushrooms are present, only a 100 are toxic and only 32 have been associated with fatalities.
• Utility values of Nepalese mushrooms tabulated by Adhikari et al (2000) are 110 as edible, 13 as medicinal, 45 as toxic and 6 others.
• Out of 110 species of edible mushrooms, 40 species are sold in local markets every season.
• Unlike European’s pastime of mushroom hunting or lacto vegetarian's craze for “organic” food, in developing country like Nepal, either poor man’s delicacy or hunger often drives people to forage for wild mushrooms.
Mushrooms in Nepal
• Exact magnitude of problem in Nepal is unknown.
• In Nepal, the mortality had been found to occur around 15-20 annually (Adhikari, 2004).
• Undocumented and unrecorded mushroom poisonings are much more common than the published incidents because so many cases occur in very remote areas.
Magnitude of problem in Nepal
There is a proverb
“Bahun le chyau khaosna swad paos”
Means: if the Brahmines have eaten the mushrooms, they could have known the actual taste of mushrooms”.
Experience from BPKIHS
• In 2008-9 Seventy cases of Mushroom poisoning were admitted in various wards.
– Medicine ward: 49 cases (5 expired)
– Paediatric Ward: 21 cases (3 expired)
• How are Mushroom Poisonings classified clinically And What is the specific management strategy for each group?
• Because mushroom species vary widely in the toxins they contain and because identifying them with certainty is difficult, a clinical rather than taxonomic system of classification is useful.
• Eight groups of toxins are identifiable:
1. Cyclopeptide-containing Mushrooms
2. Monomethylhydrazine-containing Mushrooms
3.Muscarine-containing Mushrooms
4. Coprine-containing Mushrooms
5. Ibotenic Acid and Muscimol- containing Mushrooms
6. Psilocybin-containing Mushrooms
7. Gastrointestinal Toxins
8. Orelline & Orellanine- containing Mushrooms
Group I - Cyclopeptide-containing Mushroom
• Most difficult to treat.
• 95% of all fatality due to mushroom poisoning
• Species include Amanita phalloides, A verna, A virosa, Gallerina Autumnalis
• Toxins include amanitins and phallotoxin which inhibit RNA polymerase II
• Toxin is stable to cooking, pickling, salting and is not hydrolyzed by digestion
Amatoxin Clinical Effects :
• Delay of 6 to 12 hours before initial symptoms is common
• Phase 1: Severe Gastroenteritis- profuse watery diarrhoea, nausea, vomiting, thirst,
• Phase 2: transient improvement in symptoms– Latent period of web being lasting 1 to 5 days
• Phase 3: Recurrence symptoms, manifested with hepatic, renal toxicity, seizures, coma and death
Amatoxins - Treatment :
• Toxin elimination via repeat dose charcoal
• Supportive care with fluids, electrolytes
• Penicillin G may displace amanitin from plasma binding sites 1 million Unit/kg/d
• Thioctic acid
• Silymarin compete for membrane transport
• Liver Transplant
• Forced diuresis, hemodialysis, plasmapheresis- – Not useful
Group II Monomethylhydrazine containing Mushrooms :
• Gyromitra esculenta, G californica• Brain like appeaance• Gyromitrin: Chelate with pyridoxal phosphate- disrupt
GABA function
• Clinical Effects: long latent period of 6 to 12 hours followed by vomiting, watery diarrhea, abdominal pain, weakness and headache.
• Severe cases notable for jaundice, hyperreflexia, vertigo, loss of muscle coordination, seizures and coma
• Recovery in 2 to 6 days
Gyromitra esculenta
Treatment
• Standard decontamination measures
• For seizures, Pyridoxine at 25mg/kg in 15 to 30 minutes IV.
Group II Monomethylhydrazine containing Mushrooms :
Group III- Muscarine containing:
• Clitocybe dealbata, Omphalotus olearius
• Toxin is muscarine which stimulates postganglion parasympathic fibers
Omphalotus olearius
Muscarine Clinical Effects:
• Onset within 30 to 120 minutes
• Clinical Feature: like OP Poisoning
• Recovery in 6 to 24 hours
Muscarine Treatment :
• Standard decontamination methods
• In symptomatic patients– Atropine 1mg to 2mg for adults – and children
• 0 to 2 years .2 mg • 3 to 4 years .3 mg • 5 to 10 years .4mg
Group IV – Coprine-containing Mushrooms :
• Coprinus atramentarius “Inky caps”
• Toxin is coprine,
• The metabolite of which inhibits aldehyde dehydrogenase
• Ingestion is asymptomatic unless ethanol is consumed in the following 2 hours to 5 days– Disulfiram like effect
Coprine Treatment :
• Decontamination
• Symptomatic treatment – B-blockers or sedatives for anxiety and
tachycardia
• Fluids for hypotension
Group V - Muscimol/Ibotenic Acid-containing Mushrooms :• Amanita Muscaria, Amanita Pantherina,
Amanita Gemmata
• Toxin is Ibotenic acid which is metabolized to Muscimol
• Muscimol is a false neurotransmitter which stimulates GABA receptors and usually results in anticholinergic symptoms
Clinical Effects :
• Onset within 30 to 90 minutes, most marked at 2 to 3 hours
• Drowsiness, confusion resembling alcohol intoxication, dizziness, ataxia, euphoria, muscle cramps and spasms, delirium, visual disturbances, hallucinations
• Vomiting is rare • Deep sleep or coma terminates the episode
which usually lasts from 4 to 8 hours
Musicmol/Ibotenic Acid Treatment :
• Standard decontamination measures
• Support airway and hemodynamics with standard measures
• With life threatening anticholinergic signs, consider physostigmine .5 to 2 mg slow IVP over 5 minutes
Group VI - Psilocybin containing Mushrooms:
• Psilocybe caerulescens, Panaeolus, Gymnopolis • “Magic mushrooms” • Toxins are Psilocybin and its metabolite psilocin • Effects are serotonin and norepinephrine mediated • Effects like LSD
Psilocybe caerulescens
Psilocybin Clinical Effects :
• Onset of symptoms within 30 to 60 minutes, occasionally as late as 3 hours
• Symptoms include hallucination, impaired judgement, hyperkinesis, laughter, vertigo, ataxia, muscle weakness and drowsiness
Psilocybin Treatment :
• Decontamination not recommended as this may increase agitation
• Rest and reassurance in a dark, quiet room
• Consider benzodiazepines for severe anxiety
Group VII - GI Irritants :
• Largest group with a diverse type of mushrooms (little brown mushrooms)
• Chlorophyllum molybdites, Agaricus Xanthodermis, Russula Emetica
• No specific toxins identified • Most mushrooms cause more symptoms when eaten
raw
• Onset of symptoms within 30 minutes to 2 hours after ingestion
Chlorophyllum molybdites
GI IrritantsTreatment :
• Standard decontamination measures
• Beware of antiemetics and antidiarrheals as these may have unpredictable interactions with mushroom toxins
Group VIII- Orelline & Orellanine-containing Mushrooms :
• Cortinarius species - over 1000 in the US
• Causes severe renal tubular damage resulting in reduced GFR, decreased absorption of water/NA/K, proteinuria, glucosuria
Cortinarius armillatus
Orellanine Clinical Effects :
• Initial mild gastroenteritis
• Long latent period of 36 hours to 21 days
• Symptoms include severe thirst, abdominal or flank pain, chills and fever
• Progresses to acute renal failure.
• Chronic failure occurs in 50% of cases
• Recovery takes weeks to months
Orellanine Treatment :
• Standard decontamination
• Hemodialysis
• Renal transplant
• Steroids, hemoperfusion, and forced diuresis do not improve outcome
• Identification of mushroom species & “What is edible & what is not?”
Mushrooms Identification
General Morphology :
Mushrooms are described by
Size, color, color changes, texture, order, taste, gap, gills, stem/stipe, veil, annulus, volva, mycelium, and spore prints
Cap : Shape, Surface and Margins
Gills :
• Gills are described by the attachment pattern to the stalk and by spacing, thickness, depth and forking pattern
Stem/Stipe :
• Stipe features include size, color, color changes, shape, position, structure, and surface characteristics
Veils and Volva :• A veil is residual tissue
from mushroom development that is left on the stalk and varies from a few remnants to a complete annulus
• A volva is the partial remnant of the veil found around the base of the stalk
Spore Prints :
• Spore prints are a very powerful way to identify species of mushrooms. They are created by leaving a mushroom on top of a piece of paper for 2-6 hours
Habitat Questions :
• Where were the mushrooms growing?
• Were they in a yard, lawn or wild area?
• Had pesticides or herbicides been applied?
• If trees were nearby, what were they?
• Was the mushroom growing on wood, ground or other material?
• If wood, was the wood living or dead?
• Identification of mushroom species?
• What is edible & what is not?
Species Identification• Colorful field guide is helpful.
– David Arora's Mushrooms Demystified, 2nd edition (1986) .
– Taylor Lockwood's Treasures from the Kingdom of Fungi
• Web Browsing– http://www.mushroomfieldguides.com/– http://americanmushrooms.com– http://www.mushroomexpert.com/– http://www.mykoweb.com/
• Online Mycologist– Los Angeles Mycological Society (LAMS)
identification_request@lamushrooms.org
Species Identification• The toxins can be detected in poisoned
patients from GI fluids, serum, urine, stool, liver and kidney biopsies using – High-performance liquid chromatography (HPLC)– Thin-layer chromatography– or Radioimmunoassay (RIA).
• Species-specific identification of the major cooked and fresh poisonous mushrooms in Japan was performed using a – Real-time PCR.
Ralph's Rule for (relatively) Safe Mushrooming • If uncertain of the identity of a species, don't try it..• Stick with mushrooms you know well and expand
your repertoire slowly• For a new species, you should be able to find
it via the keys in at least three books. • When trying a new mushroom always eat a very
small amount of one, and only one mushroom, and wait 24 hours before eating more. Save some specimens so they can be identified if trouble develops.
• Eat only fresh & cooked mushrooms (not old or moldy)
Mushroom hunting is a true sport: The fungi do have an equal chance to win. If we are correct in our identification, at very best we win a tasty side-dish, or an optimally seasoned main course. On the other hand, if we are not correct, we win repeated trips to the head, maybe a trip to the emergency room, and in the extreme, a trip to the mortuary .
"There are old mushroom hunters, and there are bold mushroom hunters, but there are no old, bold mushroom hunters"
The End