Mushroom Toxicity

As we approach the end of Italian Truffle hunting season (according to google…) let’s talk about some of the toxicology of Mushrooms based on a brief talk from our tox boss Dr. Swoboda. Most often, inedible and even edible (but decomposing…) mushrooms cause a syndrome of abdominal pain, nausea, vomiting, and diarrhea. Typically this starts soon after ingestion and can resolve within hours to days. Give these patients some love, supportive care and anti-emetics as needed. But, as it turns out, there are thousands of mushrooms and thousands of (rare) ways that they can harm you so to keep it simple I’ve divided it up by time of onset. Generally speaking- early onset equals better outcome. 

Early Onset (<6hr)

Some common early onset syndromes include Muscarinic, Glutaminergic, Gyromentin and Hallucinogenic. 

Muscarinic

For Muscarinic presentation, think cholinergic toxicity: Salivation, lacrimation, Urination… (Ringing a bell yet? SLUDGE, DUMBBBELLS. Look it up!) Effects are caused by ingestion of Slitocybe and Inocybe mushrooms, often within 2 hours of ingestion and can last for several hours. Fatalities are uncommon- but rehydrate them for some of the fluids that they are losing and look out for those “killer B’s” aka  bronchorrhea, bronchospasm, bradycardia. If they need secretion control – you can give IV atropine boluses .01- .02 mg/kg. 

Glutaminergic

Glutaminergic toxicities are often noted in children who pick up the classic home of smurfs, and candy of Alice: the Amanita Muscaria mushroom. These excitatory manifestations from ibotenic acid are often mingled with intermittent GABA-ergic effects (dizziness, somnolence, dysphoria, hallucinations.) As the A. Muscaria also release muscimol. Both the somnolent and agitative effects are shortlived and fatalities are rare. Again the answer is supportive care- unless seizing for which you can give benzos. 

Gyrometrin

Gyrometrin toxicities from the Morel-look-alike Gyrometra mushrooms cause seizures. In short, since I’m not a lover of pathophys, the active metabolite inhibits the activation of B6 thereby blocking the synthesis of GABA – therefore– seizures! So, although you can try benzo’s for these seizures, the most important thing is to give pyrodoxine!

Psilocybin

Psilocybin intoxications are frequently experienced on prupose… these hallucinogenic mushrooms however can also act as serotonergic agonists, which – especially if the patient is on an SSRI – can lead to serotonin syndrome. So if they have myoclonus, tachycardia etc. with their hallucinations look a little farther than their high. 

Late Onset (> 6hr )

Phylloides

Death Cap… Amanita Phalloides has enough toxicity in one single mushroom that it could kill an adult. So let’s not eat these, friends. If a patient does happen to eat one, the toxidrome comes in a 3 step death signal. The patient will intially present with GI symptoms about 6 to 24 hours after ingestion (N/V/D.) Phase two will be signified with a false recover period. However during this time the patient’s Liver enzymes will be stealthily rising between 18 to 36 hours. Then comes phase 3: severe gastroenteritis with hepatic failure, renal failure and pancreatic insufficiency. This phase may cause death within 1 week of ingestion. So here’s the thing… nothing works. You can try charcoal in acute ingestion, maybe biliary drainage. If you are a miracle worker and can get them a liver transplant, please do. New options are coming out though, Silybin for instance has been found to increase the ratio of survivors. Beautifully, this is an extract from milk thistle. Oh, how mother nature provides! However, it’s not easily available state side. 

Cortinarius

Renal failure from Cortinarius mushrrom toxicity again will typically initally present with upset stomach complaints. The nausea, vomiting, chills will typically present 24 to 36 hours after ingestion. In days to weeks the patient will develop interstitial nephritis and tubular necrosis. Most patient’s renal failure requires dialysis for the short term – however some may need dialysis chronically or even kidney transplant.

Conclusion

There are new mushroom toxidromes being written about on the reg- ranging from delayed onset rhabdomyolysis to vision loss. As most mushroom toxidromes may intitally present with simple upset GI symptoms it may be hard to catch the ingestion early on. Also there is no fecal mushroom test or anything like that. Mushroom toxicity is rare, and even then most presentations are simple GI tox without worsening. So stay the course, don’t ignore elevated LFTs. And if they talk about mushroom hunting, then get yourself ready!

Citations

• Diaz, J. Syndromic diagnosis and management of confirmed mushroom poisonings. Critical Care Medicine. 2005. 33(2):427-436
• Enjalbert, F. Rapior, S. Nouguier-Soule, J. Guillon, S. Amourous, N. Cabot, C. Treatment of Amatoxin Poisoning: 20-year retrospective analysis. Journal of Toxicology: Clinical Toxicology. 2002. 40: 715-757
• Horowits, KM. Horowitz, B.Z. Gyromitra Mushroom Toxicity. Treasure Island, FL: StatPearls Publishing. (2019) Retrieved from: https://www.ncbi.nlm.nih.gov/books/NBK470580/?report=reader