Mushroom toxicity

Background

Major Categories

1. Early-Onset Poisoning
   1. Toxicity begins within 2hr of ingestion; clinical course is usually benign
2. Late-Onset Poisoning
   1. Toxicity begins 6hr after ingestion; clinical course is often serious/ possibly fatal

Mushroom Toxin	Pathologic Effect
Amatoxin	Hepatotoxicity
Coprine	Disulfiram-like
Gyromitrin	Seizures
Ibotenic Acid	Anticholinergic
Muscarine	Cholinergic
Orellanin	Naphrotoxicity
Psilocybin	Hallucinations

Differential Diagnosis

Causes of acute hepatitis

• Acetaminophen toxicity (most common cause of acute liver failure in the US)
• Viral hepatitis
  • Hepatitis A
  • Hepatitis B
  • Hepatitis C
  • Hepatitis D
  • Hepatitis E
  • HSV
  • Epstein-Barr virus
  • Varicella zoster virus
• Toxoplasmosis
• Acute alcoholic hepatitis
• Toxins
  • Mushroom toxicity
  • Crotinarius mushrooms
    • Gyromitra mushrooms
    • Amanita mushrooms
• Ischemic hepatitis
• Autoimmune hepatitis
• Wilson's disease

Early-Onset Poisoning

• Comprises majority of mushroom-induced intoxications

Clinical Features

• Depends on the type of mushroom ingested
• GI
  • Nausea/vomiting/diarrhea
  • Resolves within 24hr
• CNS
  • Euphoria, hallucinations
  • Lasts 4-6hr
• Muscarinic
  • SLUDGE symptoms
  • Diaphoresis, muscle fasciculations, miosis, bradycardia, bronchorrhea
  • Resolves in 4-12hr
• Disulfiram-like effect
  • Usually when drinking alcohol
  • Flushing, tachycardia, diaphoresis, hypotension

Treatment

• GI predominant symptoms:
  • Activated charcoal 0.5-1gm/kg
  • Do not give antidiarrheal meds
• CNS predominant symptoms:
  • Place in dark, quiet room
  • Benzos may be given to pts who are agitated
• Muscarinic predominant symptoms:
  • Consider atropine for severe symptoms; 0.5-1mg IV for adults; 0.01mg/kg IV for peds

Disposition

• Discharge once symptoms have subsided

Delayed-Onset Poisoning

• Amanita species causes 95% of deaths
  • Toxin inhibits formation of mRNA and is heat stable

Amanita phalloides

Amanita phalloides aka death cap

Clinical Findings

• Stage 1 (GI)
  • Occurs 6-24hr after ingestion and lasts 12-24hr
  • The later the onset of symptoms the better the outcome
  • GI predominant symptoms:
    • Abd pain, vomiting and diarrhea (which may become bloody)
• Stage 2 (convalescent)
  • Occurs 48hr after ingestion and lasts 12-24hr
  • Symptoms subside and pt appears better
  • Liver deteriorates silently and precipitously (LFTs begin to rise)
• Stage 3 (failure)
  • Occurs 2-4d after ingestion
  • Fulminant liver failure
    • Hyperbilirubinemia, coagulopathy, hepatic encephalopathy, hepatorenal syndrome

Treatment

• Immediate therapy
  • Activated charcoal
    • Some advocate repeated doses during the first 24hr
      • Amatoxin undergoes enterohepatic circulation
  • Penicillin
    • High doses 1 mil units/kg/d effective in animal studies (inhibits amatoxin uptake)
  • Silibinin (milk thistle)
    • Free radical scavenger used successfully in Europe; 25-50mg/kg/d
• Ongoing therapy
  • Glucose monitoring
    • Hypoglycemia is one of the most common causes of death in early mushroom toxicity
  • Liver/renal failure monitoring
    • Serial LFTs, chem, coags
  • Prepare for liver transplant
    • Progressive coagulopathy, encephalopathy, renal failure are indications for transplant

Disposition

• Admit all pts suspected of ingesting amatoxin containing mushrooms for at least 48hr

Gyromitra mushrooms

Gyromitra mushrooms

• also known as "brain fungi"
• inhibits formation of Vitamin B6 and BAGA

Clinical findings

• GI upset, fatigue, muscle cramps
• Can present with refractory seizures

Treatment

• Supportive care
• High dose pyridoxine for refractory seizures (5g IV initially)

Crotinarius mushrooms

Cortinarius mushroom

• contain toxin Orellanine

Clinical findings

• Headache, chills, malaise, nausea and vomiting over days
• Can see delayed renal failure 1-3 weeks after exposure

Treatment

• Supportive
• If renal failure from mushroom exposure, recovery can take several weeks. May need temporary hemodialysis.

Source

Tintinalli Haddad and Winchester's Clinical Management of Poisoning and Drug Overdose