Poisonous mushrooms Flashcards
What is the most challenging aspect of mushroom poisoning?
Identification of mushrooms
Death Cap mushrooms
*Most toxic mushroom in the world
-present on West and East coast
-wet warm weather
-near oak, birch, pine substrate
-mostly affects dogs
Mechanism of death cap mushroom
Amatoxins undergo irreversible inhibition of RNA polymerase II = inhibits protein synthesis= necrosis of liver, kidney and GIT
Toxicity of death cap mushroom
-one mushroom can be lethal
What are the 4 classical signs of death cap mushrooms?
1.Latency period (6-12 hrs post ingestion)
- GI phase (6-24 hrs post ingestion)
- Honeymoon phase (24-48hrs post ingestion, lasts 12-24hrs)
- Terminal phase/ hepatorenal phase (36-72hrs post ingestion)
Latency period of death cap mushrooms
-No clinical signs
-detection of alpha-amantins in urine
GI phase of death cap mushroom
Appears as dietary indiscretion/food poisoning
-vomiting
-bloody diarrhea
-abdominal pain
-anorexia
-dull/lethargic
Honeymoon phase of death cap mushrooms
24-48hrs post ingestion, lasts 12-24hrs
*false recovery
*need to monitor bloodwork for elevated liver enzymes
Terminal phase/hepatorenal phase
36-72hrs post ingestion
-fulminant liver failure
-increased liver enzymes, hypoglycemia, hypoalbuminemia, hypocholesterolemia, hyperbilirubinemia, increased PT/PTT
-renal failure
*die due to acute liver failure
Histological regions of death cap
-Centrolobular to massive hepatocellular necrosis with collapse of hepatic cords, hemorrhage
-renal proximal tubular epithelial necrosis
-necrotic enteritis of GIT
Death cap PM finding
Hemorrhagic, swollen liver
Death cap management
-no antidote
-early decontamination (often miss window because latency period)
-supportive care= hepatoprotectants, IVFT,
-octreotide- used to inhibit gallbladder contraction so lack of gallbladder content release inhibits further absorption
Diagnosis of death cap mushrooms
-history
-latency of liver failure followed by gastroenteritis
-mushroom ID
-detection of amatoxins in stomach, liver, kidney, urine, serum
Prognosis of death cap mushrooms
poor to grave= high mortality
Fly agaricus and Panther cap
-characteristic warts; multiple colours (red, orange, brown)
-Pacific northwest; conifer and deciduous forests
-fishy odour which attracts dogs
-used as recreational psychotropic in humans
Mechanism of fly agaricus and panther cap
Have opposing actions on the CNS
1. Ibotenic acid= NMDA glutamate receptor agonist= excitatory
- Muscimol= GABA agonist= inhibitory
Toxicity of fly agaricus and panther cap
One mushroom can be lethal
Fly agaricus and panther cap clinical signs
Alternating phases of CNS depression and stimulation
-vomiting, diarrhea, hypersalivation
-miosis, lethargy, hallucinations, tremors, agitation
-can lead to resp failure, bradycardia, seizures, coma
Management of fly agaricus and panther cap
-no antidote
-early decontamination
-sedation with acepromazine
-methocarbamol for tremors
-supportive care
Why do you need to be careful about using GABA agonist/anti seizure drugs (diazepam) for fly agaricus and panther cap toxicity?
Because toxicity results in alteration between CNS excitation and depression. Can potentially make CNS depression worse!
Diagnosis of fly agaricus and panther cap
-history of exposure
-rapid neuro clinical signs
-mushroom ID
-detection of contents in stomach contents
Prognosis of fly agaricus and panther cap
Variable depending on response to symptomatic and supportive care
*death possible
Magic mushrooms
-contains psilocybin and psilocyn toxins
*toxicity info for animals= low
*heat sensitive so cooking will decrease toxins
Mechanism of magic mushrooms
Agonist of serotonin receptors
Clinical signs of magic mushrooms
Within 30mins to few hours
-mydraisis, ataxia, vocalization, nystagmus
-seizures at high doses
-aggression
-hyperthermia, tachycardia
**rarely fatal
Magic mushroom management
-decontamination
-no antidote
-usually self limitiing in a few hours
-supportive care (low stimulation environment, sedation, thermoregulation, seizure management)
Other mushrooms frequent clinical signs
**can appear like very toxic death cap of fly agaricus but they are not
Usually acute gastroenteritis
-manage with decontamination, supportive care
-prognosis good with treatment
Mushroom ID
Sample for ID
-wrap mushroom in damp towel and place in plastic bag
-retrieve as much as possible
-note where it was found (surrounding trees etc.)
