About This Guide
This guide covers the 3 most clinically significant toxic mushroom species documented in Oceania — the lethal amatoxin-producing Amanita marmorata (Marbled Death Cap), the severe gastrointestinal toxin producer Chlorophyllum molybdites (False Parasol), and the nephrotoxic orellanine-containing Cortinarius species (Webcap Mushrooms). Together these species represent the dominant toxicological threats across New Zealand, Australia, Papua New Guinea, Fiji, Samoa, and the Solomon Islands.
Data-only reference — no photographs. Species identification for clinical management must be confirmed by a toxicologist, mycologist, or poison control specialist, not from this text alone.
Looking for photos? Browse our Mushroom Species Directory or use the Search Portal.
New Zealand National Poison Centre (tap to call): 0800 764 766 — 24 hours, 7 days, toll-free.
Quick Reference — 3 Species
| Species | Common Name | Tier | Toxin Class | Onset | Primary Risk |
|---|---|---|---|---|---|
| Amanita marmorata | Marbled Death Cap | Tier 1 | Amatoxins (RNA polymerase II inhibition) | Biphasic: 6–24h GI / 48–96h hepatic | Fulminant hepatic failure, AKI, death |
| Chlorophyllum molybdites | False Parasol | Tier 2 | Molybdophyllysin (metalloendopeptidase) | 30 min – 2.5 hours post-ingestion | Severe GI toxidrome; hypovolemic shock |
| Cortinarius spp. | Deadly Webcap / Fool's Webcap | Tier 1 | Orellanine (renal proximal tubular necrosis) | 2–3 weeks delayed — longest latency of any toxic mushroom | Irreversible renal failure; permanent dialysis / transplant |
Morphology: Cap 4–12 cm with a distinct marbled grey, silver-white, or pale brownish pattern. Crowded white free gills. Thin, fragile ring on the upper stem that tears easily. Persistent, thick, sac-like white volva at the base of the stem.
Lookalike Confusion: Readily confused with edible wild white mushrooms or non-toxic native variants by local foraging communities unaware of invasive mycorrhizal setups involving introduced pine plantations.
Clinical Presentation — Triphasic Amatoxin Syndrome
Phase 1 — 6 to 24 Hours: GI Storm
Severe delay before sudden onset of watery, cholera-like diarrhea, painful abdominal cramps, and rapid fluid depletion. Patient may appear acutely distressed.
Phase 2 — 24 to 48 Hours: False Recovery
Gastrointestinal signs improve. Patient feels better. This is deceptive. Liver enzymes (AST/ALT) and INR begin to climb silently during this phase. Do not discharge.
Phase 3 — 48 to 96 Hours: Hepatorenal Failure
Fulminant hepatic failure, jaundice, encephalopathy, acute kidney injury, and profound coagulopathy. Liver transplant triage must begin during Phase 2 before this stage is reached.
ICU Protocol
- High-volume IV fluid resuscitation targeting urine output of 100–200 mL/hr to enhance toxin clearance.
- Multi-dose activated charcoal (MDAC) via nasogastric tube at 1 g/kg every 4 hours to interrupt enterohepatic recirculation.
- Continuous IV Silibinin (Legalon SIL) at 20–30 mg/kg/day OR high-dose Benzylpenicillin (Penicillin G) at 300,000–1,000,000 units/kg/day.
- IV N-acetylcysteine (NAC) using standard liver-failure regimen.
- Monitor PT/INR, AST/ALT, total bilirubin, and creatinine every 6 hours.
- Screen early for liver transplant eligibility using King's College Criteria.
Morphology: Large, sturdy cap (10–30 cm) with patchy, irregular brown scales on a white backdrop. Gills turn a distinct dull olive-green at maturity. Spore print is green — a definitive distinguishing feature.
Lookalike Confusion: Misidentified as the prized edible Macrolepiota (True Parasol) or wild Agaricus species due to lookalike shaggy caps when young. Confusion is most common during peak fruiting after heavy rains in village settings.
Clinical Presentation
Onset: 30 Minutes to 2.5 Hours Post-Ingestion
Sudden projectile vomiting, explosive watery green or bloody diarrhea, agonizing abdominal cramps, and rapid onset of hypovolemic shock. Electrolyte derangement — especially severe hypokalemia — is the primary ongoing risk.
ICU Protocol
- Aggressive fluid resuscitation with IV balanced crystalloids to correct rapid volume loss and prevent shock progression.
- IV antiemetics: Ondansetron 4–8 mg or Metoclopramide.
- Continuous monitoring of serum electrolytes — especially potassium (K+). Severe hypokalemia requires IV potassium replacement.
- Self-limiting profile: typically resolves completely within 24–48 hours with aggressive supportive care. No antidote required.
- No hepatic or renal damage expected. Liver function tests should remain normal; any elevation warrants reassessment of species identification.
Morphology: Medium cap 3–8 cm, rusty orange-brown to brick red, dry silky surface. Gills rusty cinnamon-brown. Prominent cobweb-like cortina veil remnants on stem. Rusty brown spore print.
Lookalike Confusion: Misidentified as edible Cortinarius or Gymnopus species in the field. The rusty brown gills and cobweb cortina veil are the key differentiators.
Clinical Presentation — Orellanine Delayed Nephrotoxic Syndrome
Hours 1 to 36: Initial Mild Prodrome
Mild nausea, vomiting, abdominal discomfort, intense thirst, and polyuria. Symptoms are non-specific and often dismissed. Many patients do not seek medical attention at this stage.
Days 2 to 21: Asymptomatic Latent Phase
Apparent full recovery. Patient is entirely asymptomatic while orellanine accumulates silently in renal tubules. This latent window is the longest of any toxic mushroom in the entire library — up to 3 weeks. Patients presenting with renal failure at this stage frequently have no memory of eating a mushroom.
Weeks 2 to 3: Renal Failure Onset
Progressive oliguria, flank pain, rising creatinine and urea. Renal tubular necrosis becomes clinically evident on laboratory panels.
Weeks 3 to 8: Irreversible Renal Failure
Irreversible renal failure. Permanent dialysis dependency develops in many patients. Renal transplantation is often required. Prognosis correlates directly with the dose ingested and the speed of nephrology intervention.
ICU Protocol
- No specific antidote exists for orellanine.
- Early nephrology consult mandatory — do not wait for confirmed renal failure; consult immediately on any suspected ingestion.
- Aggressive IV fluid hydration to support renal perfusion throughout the latent phase.
- Serial renal function monitoring: creatinine, urea, GFR, urinalysis every 48 hours during the latent window.
- Renal replacement therapy (hemodialysis) when creatinine rises — initiate early, do not wait for oliguria.
- Early renal transplantation evaluation — many patients require permanent transplantation; refer to transplant unit before end-stage failure is reached.
- If ingestion is known or suspected within 24 hours: activated charcoal and gastric lavage.
- Corticosteroids have been trialed in some European cases with limited evidence; decision at nephrology discretion.
Veterinary Notes
Dogs
Orellanine causes identical delayed renal tubular necrosis in dogs. Onset 3–14 days post-ingestion. Progressive azotemia, polyuria then oliguria, anorexia. Management: aggressive IV fluid diuresis, renal function monitoring, hemodialysis at specialist veterinary centers. Prognosis poor to grave for large ingestions.
Cats
Severe renal proximal tubular damage. Delayed presentation 5–14 days. Cats metabolize orellanine poorly and are particularly vulnerable. Immediate veterinary referral required even for suspected minor exposures.
Cross-Reference
Cortinarius species also appears in the Europe guide (Cortinarius orellanus documented across Scandinavian and Central European beech forests) and the Russia guide (Cortinarius rubellus in Siberian taiga).
Poison Control
- Australia: Poisons Information Centre — 13 11 26 (24 hours)
- New Zealand: National Poisons Centre — 0800 764 766 (24 hours)
Clinical Triage Algorithm — Pacific Island Ingestions
Suspected Wild Mushroom Ingestion — Primary Decision Branch
- Rapid dehydration danger
- Gills mature to olive-green
- Green spore print
- No hepatic damage expected
- Give IV balanced crystalloids
- Give IV Ondansetron 4–8 mg
- Monitor serum potassium (K+)
- Discharge at 24–48 hours if stable
- Silent cellular destruction
- Gills stay white; base has a volva
- Rising AST/ALT/INR at 24 hours
- ADMIT TO ICU IMMEDIATELY
- Start continuous IV Silibinin
- Run MDAC via NG Tube
- Check PT/INR every 6 hours
Lookalike Confusion Matrix
| Toxic Species | Confused With | Key Differentiator | Clinical Consequence of Error |
|---|---|---|---|
| Amanita marmorata | Edible white field mushrooms; non-toxic native white Amanita variants | Sac-like volva at base of stem; marbled cap pattern; GI onset delayed beyond 6 hours | Missed amatoxin diagnosis during false recovery phase → fulminant hepatic failure |
| Chlorophyllum molybdites | Macrolepiota True Parasol; wild Agaricus species | Olive-green gill color at maturity; green spore print (vs. white/pink in safe look-alikes) | Hypovolemic shock and severe hypokalemia from under-treated GI toxidrome |
| Cortinarius rubellus / C. orellanus | Edible Cortinarius species; Gymnopus species | Rusty brown gills; cobweb-like cortina veil remnant on stem (vs. no veil in Gymnopus); rusty brown spore print | Missed orellanine diagnosis during 2–3 week latent phase → irreversible renal failure, permanent dialysis dependency, transplantation |
Regional Emergency Contacts
Bilingual Clinical Discharge Summary Template — English / Fijian
Clinical Discharge Summary / I Tukutuku ni Sere mai na Vale ni Wai
🚨 Red Flag Return Criteria
English: Return to the emergency room immediately if you develop any yellowing of the eyes or skin (jaundice), dark urine, confusion or disorientation, bleeding from the gums, or extreme weakness.
Fijian: Lesu totolo ki na valenivai ni leqa tubukilsan ke o raica ni dromodromo na matamu se kuli mu, loaloa na memu ulu, veilecayaki na vakasama, malumu vakasivia, se kamunaga na baci ni bati mu.
Copy the full guide text for use in clinical handoffs, EHR notes, or team communications.