Gyromitra Esculenta
Today we are discussing a poisonous mushroom named Gyromitra esculenta (false morel). Originally, they were thought to be a very edible mushroom, even being encouraged to be eaten during times of famine across Poland and Scandinavia. Esculenta even means “good to eat” in latin. They are even sold as “morschels” in Europe.Despite all of this misdirection, they are poisonous. They are the target of many a novice forager, pet, or small child and can arrive for medical evaluation without clear history.
First, let's be shallow and talk about looks because Gyromitra obviously tried to mess with Darwin and grow into a brain - hence "gyrus."
They are confused with the regular Morel (an edible/desirable mushroom) quite often.
The toxin in the Gyromitra Esculenta is..... gyromitrin. It is both moderately volatile and heat sensitive. The thought being that if you cook and discard the liquid, your savory poverty truffles will be less toxic. Alas I do not recommend this as symptoms can still occur and there is great variation in the concentration of toxin within each mushroom - perhaps even cumulative poisoning.
Mechanism: The metabolites of the toxin competitively inhibit pyridoxal phosphate and drop GABA levels (need pyroxidine to convert L-glutamate to GABA). The GABA deficiency leads to low seizure threshold. Oxidated metabolites in the liver then cause hepatic necrosis. If you survive all that, the toxin is also carcinogenic.
LD-50 (dose required to kill 50% of the people):
ADULT: 20-50mg/kg (0.4-1kg of fresh mushrooms)
PEDIATRIC: 10-30mg/kg (0.2 – 0.6 kg of fresh mushrooms)
Symptoms: Nausea, Vomiting, and Diarrhea (delayed 4-50 hours) Average onset 5-12 hours Neurologic symptoms (coma, headache, ataxia, delirium, seizures) The brain looking mushroom causes brain related problems. Hepatic failure 2-4 days afterwards and hypoglycemia
Treatment: Activated Charcoal 1g/kg PO if <60 min from ingestion Seizures/neurologic symptoms: pyridoxine 25mg/kg IV with repeat doses up to 20g/day
Further Work-Up: Send CBC, BMP, LFTs, Coags Transfer to liver transplant center if AST/ALT >2000, or PTT > 50
Auerbach, P. S. (2007). Wilderness medicine. Ch 66: Toxic Mushroom Ingestions 1464-1490.e3
https://www.michiganmorels.com/morels2.shtml
https://lifeinthefastlane.com/ccc/mushroom-toxicity/