DESCRIPTION

• Amanitin/phalloidin:
  • Species:
    • Amanita phalloides ("death cap")
    • Amanita virosa/Amanita verna ("destroying angel")
    • Galerina marginata, Galerina venenata
  • Mechanism:
    • Cyclopeptide toxins inhibit RNA polymerase 2, which kills GI epithelium, hepatocytes, nephrocytes
• Gyromitrin:
  • Species:
    • Gyromitra esculenta ("false morels")
    • Other Gyromitra spp.
  • Mechanism:
    • Inhibits pyridoxal phosphate
    • Damage to RBCs, hepatocytes, neurons
• Muscarine:
  • Species:
    • Inocybe (several species)
    • Clitocybe (several species)
  • Mechanism:
    • Parasympathomimetic
• Coprine:
  • Species:
    • Coprinus atramentarius ("inky caps")
  • Mechanism:
    • Blocks acetaldehyde dehydrogenase
    • Causes disulfiram-like reaction if mixed with alcohol
• Ibotenic acid/muscimol:
  • Species:
    • Amanita pantherina ("the panther")
    • Amanita muscaria ("fly agaric")
  • Mechanism:
    • GABA agonists
• Psilocin/psilocybin:
  • Species:
    • Psilocybe and Panaeolus spp. as well as others
  • Mechanism:
    • Similar structure to lysergic acid diethylamide, effect serotonin receptor
• Gastric irritants:
  • Many various mushrooms, including those normally considered edible
• Orellanine:
  • Species:
    • Cortinarius (several species)
  • Mechanism:
    • Direct renal toxicity
• Tricholoma equestre ("man on horse"):
  • Rhabdomyolysis-inducing mushrooms
  • Unidentified myotoxin

SIGNS AND SYMPTOMS

• Amanitin/phalloidin:
  • Nausea
  • Vomiting
  • Abdominal cramps
  • Bloody diarrhea
  • Clinical course:
    • Onset of symptoms delayed 6–36 hr with development of GI symptoms
    • Transient latent phase may last 2 days (no pain/symptoms)
    • Can progress to hepatic or renal failure and death in 2–6 days
    • Most lethal mushroom toxins
• Gyromitrin:
  • 1st 5–10 hr:
    • Abdominal cramps
    • Nausea/vomiting
    • Watery diarrhea
  • Later symptoms:
    • Weakness
    • Cyanosis
    • Confusion
    • Seizures
    • Coma
• Muscarine:
  • Cholinergic symptoms include:
    • Miosis
    • Salivation
    • Lacrimation
    • Sweating
    • Diarrhea
    • Flushed skin
    • Nausea
    • Bradycardia
    • Bronchoconstriction
  • Onset usually within 1 hr (may be delayed)
• Coprine:
  • Disulfiram-like reaction within minutes to hours when combined with alcohol:
    • Flushing
    • Sweating
    • Nausea/vomiting
    • Palpitations
• Ibotenic acid/muscimol:
  • Relatively rapid onset of 30–120 min
  • GABA agonist effects include:
    • Hallucinations
    • Dysarthria
    • Ataxia
    • Somnolence/coma
  • Glutamatergic effects (mainly pediatrics):
    • Seizures
    • Muscle cramps/myoclonic movements
• Psilocin/psilocybin:
  • Rapid onset, usually resolves in 6–12 hr
  • Visual hallucinations
  • Alteration of perception
  • Mydriasis
  • Tachycardia
  • Fever and seizures in children
• Gastric irritants:
  • Group of toxins that cause nausea, vomiting, intestinal cramps, and watery diarrhea
  • Onset 30 min to 3 hr, usually resolved in 6–12 hr
• Orellanine/Amanita smithiana:
  • Nausea/vomiting
  • Headache
  • Sweating
  • Chills
  • Low-back pain
  • Polydipsia
  • Clinical course:
    • May progress to oliguria and acute renal failure
    • Markedly delayed onset of symptoms (2–14 days)
• T. equestre:
  • Acute rhabdomyolysis:
    • Myalgias/arthralgias
    • Hematuria/dark urine
    • Decreased urine output
  • Dehydration

History

• Time of ingestion
• Time of symptom onset
• Quantity ingested
• Preparation: Raw or cooked
• Picked in the wild or store-bought
• Coingestants, other mushrooms
• Alcohol/drug use history
• Symptoms of family members, friends

Physical Exam

• Vital signs
• Changes in mental status
• Pupillary response
• Cardiopulmonary exam
• Abdominal exam
• Neurologic exam

ESSENTIAL WORKUP

• Mushroom description:
  • Pileus (cap); margin shape
  • Stipe (stem)
  • Lamellae (gills)
  • Veil
  • Annulus (ring)
  • Volva
• Store mushroom in brown paper bag for future identification:
  • < 3% of cases result in an exact mushroom identification.
  • Digital photography and electronic image transfer to poison control center or regional mycologist

DIAGNOSIS TESTS & INTERPRETATION

Lab

• CBC
• Prothrombin time (PT), partial thromboplastin time (PTT)
• Electrolytes, BUN, creatinine, glucose
• Urinalysis
• LFTs, creatine phosphokinase (CPK)
• Imaging
• Spore print: Mycologist needed for specific genus/species interpretation

DIFFERENTIAL DIAGNOSIS

• Very broad differential
• Gastroenteritis
• Hepatitis/acetaminophen hepatotoxicity
• Acute renal failure (many causes)
• Rhabdomyolysis (many causes)
• Cholinergic syndrome (e.g., organophosphates)
• Anticholinergic syndrome
• Seizures (many causes)

[Outline]

• SIGNS AND SYMPTOMS
• ESSENTIAL WORKUP
• DIAGNOSIS TESTS & INTERPRETATION
• DIFFERENTIAL DIAGNOSIS

PRE-HOSPITAL

Bring any unconsumed mushrooms or mushroom pieces to hospital to aid in diagnosis:

• Refrigerate specimens if possible, place in brown paper bag.

INITIAL STABILIZATION/THERAPY

• ABCs
• Establish IV 0.9% NS saline
• Monitor
• Naloxone, D₅₀W (or Accu-Chek), and thiamine for altered mental status

ED TREATMENT/PROCEDURES

General Measures

• Decontamination:
  • Activated charcoal (50–100 g)
  • Gastric decontamination if early after ingestion and patient:
    • Has not yet vomited.
    • Has normal mental and respiratory status
    • Is not undergoing hallucinations
• Fluid rehydration and electrolyte replacement as necessary
• Call local poison control center at 800-222-1222 and request mycologist—digital picture may be electronically sent for identification.
• Obtain specimens (vomitus if needed) for identification.

Mushroom-specific Therapy

• Amanitin/phalloidin:
  • Administer activated charcoal PO q2–4h.
  • Hypoglycemia and elevated PT:
    • Signs of liver failure
    • Administer fresh-frozen plasma and vitamin K for coagulation disorders with active bleeding.
  • Administer calcium in presence of hypocalcemia.
  • Liver transplant for severe hepatic necrosis
  • Consider N-acetylcysteine, high-dose penicillin G, or silibinin if available (thioctic acid controversial)
• Gyromitrin:
  • Treat seizure with benzodiazepines.
    • Administer pyridoxine (vitamin B₆) in severely symptomatic patients.
  • Treat liver dysfunctions as outlined for amanitin/phalloidin group.
  • Dialysis for renal failure
• Muscarine:
  • Administer atropine in severe cases.
• Coprine:
  • Self-limited toxicity—supportive care
  • Avoid syrup of ipecac (contains alcohol)
  • β-Blockers for cardiac dysrhythmias
• Ibotenic acid/muscimol:
  • Usually self-limited toxicity
  • Provide supportive care
  • Monitor for hypotension
  • Treat moderate symptoms with benzodiazepines, if severe anticholinergic symptoms; consider physostigmine.
• Psilocin/psilocybin:
  • Self-limited toxicity
  • Dark, quiet room and reassurance
  • Benzodiazepines for agitation
  • External cooling measures if needed in children
• GI Irritants:
  • When poisoning from above groups not suspected, administer fluids and antiemetics.
  • Provide supportive care
• Orellanine and A. smithiana:
  • Closely monitor BUN, creatinine, electrolytes, and urine output.
  • Forced diuresis with Lasix contraindicated
  • Diuresis with alkalinization of urine with NaHCO₃ if signs of rhabdomyolysis
  • Hemodialysis/renal transplantation may be needed.
• T. equestre ("man on horse"):
  • Fluid hydration
  • Check and follow CPK.
  • Monitor urine output.

MEDICATION

• Activated charcoal slurry: 1–2 g/kg up to 100 g PO
• Atropine: 0.5 mg (peds: 0.02 mg/kg) IV; repeat 0.5–1 mg IV (peds: 0.04 mg/kg) q10min if secretions recur, to max. 1 mg/kg in children and 2 mg/kg in adults
• Dextrose: D₅₀W 1 amp: 50 mL or 25 g (peds: D₂₅W 2–4 mL/kg) IV
• Diazepam (benzodiazepine): 5–10 mg (peds: 0.2–0.5 mg/kg) IV
• Lorazepam (benzodiazepine): 2–6 mg (peds: 0.03–0.05 mg/kg) IV
• Naloxone (Narcan): 2 mg (peds: 0.1 mg/kg) IV or IM initial dose
• Physostigmine: 0.5–2 mg IM or IV in adults
• Propranolol: 1 mg (peds: 0.01–0.1 mg/kg) IV
• Pyridoxine: 25 mg/kg IV over 30 min
• Thiamine (vitamin B₁): 100 mg (peds: 50 mg) IV or IM

[Outline]

• PRE-HOSPITAL
• INITIAL STABILIZATION/THERAPY
• ED TREATMENT/PROCEDURES
• MEDICATION

DISPOSITION

Admission Criteria

• All symptomatic patients:
  • Protracted vomiting, dehydration, liver or renal toxicity, or seizures
• Transfer to tertiary medical center for early signs of renal or hepatic failure.
• Symptomatic infants and young children found with mushrooms:
  • Assume ingestion.
• ICU admission for known ingestion of an amanitin-containing mushroom:
  • Early liver service consultation

Discharge Criteria

Asymptomatic during 6–8 hr with 24 hr of close home observation and close follow-up (if reliable caregivers)

Issues for Referral

Potential liver or renal transplantation

FOLLOW-UP RECOMMENDATIONS

Drug detoxification programs if chronic recreational use

[Outline]

• DISPOSITION
• FOLLOW-UP RECOMMENDATIONS

• There are old mushroom pickers, and bold mushroom pickers; but there are no old, bold mushroom pickers.
• Symptoms with late onset (> 6 hr) generally indicate more lethal toxins.
• Lack of proper mycologic identification
• Timely organ transplant referrals when indicated

ICD9

988.1 Toxic effect of mushrooms eaten as food

ICD10

T62.0X1A Toxic effect of ingested mushrooms, accidental, init

[Outline]

• ICD9
• ICD10

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• Diaz JH. Syndromic diagnosis and management of confirmed mushroom poisonings. Crit Care Med. 2005;33(2):427–436.
• Goldfrank LR. Mushrooms In: Goldfrank LR, ed. Goldfrank's Toxicologic Emergencies. 9th ed. New York, NY: McGraw-Hill, 2011:1522–1536.
• Matsuura M, Saikawa Y, Inui K, et al. Identification of the toxic trigger in mushroom poisoning. Nat Chem Biol. 2009;5(7):465–467.
• West PL, Lindgren J, Horowitz BZ. Amanita smithiana mushroom ingestion: A case of delayed renal failure and literature review. J Med Toxicol. 2009;5(1):32–38.

Michael E. Nelson

Timothy B. Erickson