Toxic Mushroom Clinical Reference
Alberta & Prairies

Lab Value Monitoring: Amatoxin False-Recovery Phase

Identification: Yellow-green to olive cap (5–15 cm), white gills, skirt-like ring on stem, sack-like volva at base. Always dig for the volva. Lookalike: White button mushroom (Agaricus) — has pink/brown gills, no volva.

Clinical Syndrome: Phase 1 (6–24h): Explosive GI — vomiting, profuse watery diarrhea, cramping, dehydration. Phase 2 (24–72h): False recovery — LFTs normalizing; do not discharge. Phase 3 (72–96h+): Fulminant hepatic failure, coagulopathy, hepatic encephalopathy, multi-organ failure, death.

Alberta-specific note: A. phalloides is established in urban Calgary and Edmonton under ornamental European trees planted in parks and residential gardens. Most prairie cases involve urban foragers, immigrants familiar with edible Amanita species in their home countries, and residents gathering "white mushrooms" in parks. Take a careful foraging history including location.

Identification: Small brown LBM (Little Brown Mushroom), 2–5 cm, honey-tan cap with slight umbo, ring on stem (often fragile), rusty-brown spore print. Growing on wood (diagnostic distinction from soil-growing species). Deceptively unremarkable appearance. Lookalike: Honey mushroom (Armillaria — edible), Psilocybe species (recreational drug-seeker confusion — fatal outcome reported).

Treatment: Identical to A. phalloides protocol — see above. ICU admission. Multi-dose activated charcoal. IV NAC. IV Silibinin. Benzylpenicillin G. Serial LFTs & INR q6–12h. Liver transplant centre early.

Alberta-specific note: Galerina marginata grows throughout aspen parkland — the broad transition belt across central AB, SK, and MB where recreational foraging is most common. Fatalities have occurred when collectors confused it with edible Pholiota or when recreational drug users sought Psilocybe mushrooms from logs.

3-Phase Delayed Onset Timeline:

Phase 1 (0–3 days): Completely silent — no symptoms. Patient has no warning. Phase 2 (3–14 days): Subacute onset — nausea, fatigue, flank pain, thirst/polyuria. Creatinine rises. May be confused with UTI, pyelonephritis, or viral illness. Phase 3 (weeks–months): Progressive CKD, potential ESRD requiring long-term dialysis or renal transplant.

Identification: Rusty reddish-brown cap, cinnamon-colored gills, cortina remnants (cobweb-like veil) on stem, rusty-brown spore print. Lookalike: Chanterelle (edible — forking blunt ridges, no true gills, apricot/fruity odor) — this confusion has caused multiple fatalities in Europe.

Steam Inhalation Warning: MMH is volatile — boiling produces toxic vapours. Patients (and household members) may develop symptoms after standing over a pot of cooking False Morels without eating any. Ask about cooking activity. This is the same warning as on the Ontario guide — it applies equally in Alberta.

Identification: Brain-like or saddle-shaped cap (NOT honeycomb), reddish-brown, chambered stem (hollow in Morchella). Lookalike: True Morel (Morchella — highly prized edible) — honeycomb cap, fully hollow stem, Gyromitra cap is wrinkled/brain-like NOT pitted/honeycomb. This is the #1 spring foraging error in prairie provinces.

Clinical: GI onset (6–12h): nausea, vomiting, cramping. Followed by hemolytic anemia, methemoglobinemia (chocolate-brown blood, cyanosis), hepatorenal failure, seizures. High fatality if untreated seizures.

True Morel vs. False Morel — Differential Diagnosis

If a patient presents with symptoms after eating a mushroom matching the False Morel criteria, assume Gyromitrin toxicity. Have IV Pyridoxine (Vitamin B6) ready at 25 mg/kg to treat seizures.

Mechanism: Paxilline (and related antigens) trigger immune complex formation and complement activation, leading to intravascular hemolysis. Unlike most mushroom toxins, this is an immune-mediated reaction — the mushroom itself is not acutely toxic on first exposure, but sensitization accumulates. Fatal hemolytic crises have occurred in individuals who ate Paxillus involutus regularly for decades.

Identification: Brown cap with involuted (inrolled) margin, decurrent gills that bruise brown when pressed, brown spore print. Commonly mistaken for edible Boletus-family mushrooms by inexperienced foragers.

Prairie-specific note: var. flavivolvata is the prairie variant of Amanita muscaria — the cap is yellow-orange, not red as commonly depicted. This is an important identification distinction for Alberta and Saskatchewan foragers who may not recognize it as Fly Agaric based on color alone. White warts, white gills, ring, and bulbous base are consistent.

Clinical: CNS toxidrome — confusion, delirium, hallucinations, ataxia, sedation, mydriasis (dilated pupils). Muscarinic symptoms (salivation, lacrimation) minor. NOT a typical anticholinergic toxidrome — sweating often present. Self-limiting 6–12h. Rarely fatal but requires airway monitoring in severe cases.

Identification: Brown cap with white warts, white gills, ring, bulbous base with distinctive gutter-like volva collar. Similar structure to A. muscaria but brown cap. Lookalike: Amanita rubescens (Blusher — edible but turns pink when cut) — confirm color change before assuming edibility.

Compared to A. muscaria: A. pantherina contains higher concentrations of ibotenic acid and muscimol. Clinical syndrome is similar but often more severe — deeper sedation, more pronounced ataxia, higher risk of respiratory depression in large ingestions.

SLUDGE Syndrome: Salivation, Lacrimation, Urination, Defecation, GI distress, Emesis — classic cholinergic crisis. Also bradycardia, bronchospasm, miosis (pinpoint pupils), diaphoresis. Severe cases: bronchorrhea, respiratory failure.

Identification: Small white to pale buff funnel-shaped cap (3–6 cm), crowded decurrent gills, white spore print. Grows in grassland, lawns, often in fairy rings. Lookalike: Marasmius oreades (Fairy Ring Mushroom — common edible), field mushrooms (Agaricus species). Prairie foragers sometimes collect these from lawn edges.

Identification: Fibrous/silky (fibrillose) cap texture, typically brown to buff, often with central umbo. Gills pallid to brown, often with musty/spermatic odor. Spore print brown. Multiple prairie species in this genus — species-level ID not required clinically (all treated identically). Lookalike: Various small edible LBMs (Little Brown Mushrooms) — an extremely common and dangerous confusion group.

Treatment: Identical to Clitocybe dealbata. Atropine IV, titrate to secretions. ECG monitoring. Most cases resolve with adequate atropinization within hours.

Interior Distinction (diagnostic): Slice through the fruiting body. Scleroderma citrinum interior is solid purple-black or marbled purple-grey — NEVER pure white. Edible Giant Puffball (Calvatia gigantea) and Gem-studded Puffball (Lycoperdon perlatum) interiors are pure homogeneous white throughout when edible. Any discoloration = do not eat. This visual check prevents the majority of puffball misidentifications.

Clinical: Primarily GI symptoms — nausea, vomiting, cramping, diarrhea. Generally self-limiting but can be severe. Atropine-like effects reported at high doses (uncertain). Cardiovascular effects (tachycardia, hypotension) reported in rare cases.