Mushroom poisoning: A proposed new clinical classification.

Mushroom poisoning is a significant and increasing form of toxin-induced-disease. Existing classifications of mushroom poisoning do not include more recently described new syndromes of mushroom poisoning and this can impede the diagnostic process. We reviewed the literature on mushroom poisoning, concentrating on the period since the current major classification published in 1994, to identify all new syndromes of poisoning and organise them into a new integrated classification, supported by a new diagnostic algorithm. New syndromes were eligible for inclusion if there was sufficient detail about both causation and clinical descriptions. Criteria included: identity of mushrooms, clinical profile, epidemiology, and the distinctive features of poisoning in comparison with previously documented syndromes. We propose 6 major groups based on key clinical features relevant in distinguishing between poisoning syndromes. Some clinical features, notably gastrointestinal symptoms, are common to many mushroom poisoning syndromes. Group 1 - Cytotoxic mushroom poisoning. Syndromes with specific major internal organ pathology: (Subgroup 1.1; Primary hepatotoxicity); 1A, primary hepatotoxicity (amatoxins); (Subgroup 1.2; Primary nephrotoxicity); 1B, early primary nephrotoxicity (amino hexadienoic acid; AHDA); 1C, delayed primary nephrotoxicity (orellanines). Group 2 - Neurotoxic mushroom poisoning. Syndromes with primary neurotoxicity: 2A, hallucinogenic mushrooms (psilocybins and related toxins); 2B, autonomic-toxicity mushrooms (muscarines); 2C, CNS-toxicity mushrooms (ibotenic acid/muscimol); 2D, morel neurologic syndrome (Morchella spp.). Group 3 - Myotoxic mushroom poisoning. Syndromes with rhabdomyolysis as the primary feature: 3A, rapid onset (Russula spp.); 3B, delayed onset (Tricholoma spp.). Group 4 - Metabolic, endocrine and related toxicity mushroom poisoning. Syndromes with a variety of clinical presentations affecting metabolic and/or endocrine processes: 4A, GABA-blocking mushroom poisoning (gyromitrins); 4B, disulfiram-like (coprines); 4C, polyporic mushroom poisoning (polyporic acid); 4D, trichothecene mushroom poisoning (Podostroma spp.); 4E, hypoglycaemic mushroom poisoning (Trogia venenata); 4F, hyperprocalcitoninemia mushroom poisoning (Boletus satanas); 4G, pancytopenic mushroom poisoning (Ganoderma neojaponicum). Group 5 - Gastrointestinal irritant mushroom poisoning. This group includes a wide variety of mushrooms that cause gastrointestinal effects without causing other clinically significant effects. Group 6 - Miscellaneous adverse reactions to mushrooms. Syndromes which do not fit within the previous 5 groups: 6A, Shiitake mushroom dermatitis; 6B, erythromelagic mushrooms (Clitocybe acromelagia); 6C, Paxillus syndrome (Paxillus involutus); 6D, encephalopathy syndrome (Pleurocybella porrigens).