Plants, Mushrooms, Marine Toxins, and Envenomations
Plants
Cardiac glycoside plants (foxglove, oleander, lily of the valley) cause vomiting, bradycardia, and hyperkalemia; digoxin Fab may bind some but cross-reactivity varies. Anticholinergic plants (Datura, jimsonweed, deadly nightshade) cause dry skin, mydriasis, delirium, and urinary retention - treat with benzodiazepines and, in severe cases, physostigmine only when there is no sodium-channel blockade. Conium maculatum (poison hemlock) causes ascending paralysis with consciousness preserved; aconite causes refractory ventricular arrhythmias.
Mushrooms
Amanita phalloides amatoxin produces a deceptive latency of 6–24 hours, then vomiting, diarrhea, and hepatic failure; treatment is aggressive charcoal, N-acetylcysteine, silibinin where available, penicillin G, and transplant evaluation. Muscarine mushrooms cause a cholinergic picture, but never give atropine routinely without severe symptoms. Coprinus with alcohol causes a disulfiram-like reaction.
Marine toxins
- Ciguatera: gastrointestinal symptoms followed by cold-to-hot reversal dysesthesia; mannitol is not proven.
- Scombroid: histamine from spoiled fish, mimics allergy within minutes, responds to antihistamines.
- Tetrodotoxin (pufferfish) blocks sodium channels; no antidote.
- Paralytic shellfish poisoning causes ascending paralysis.
Envenomations
Crotalid snakebite: progressive swelling, coagulopathy, and thrombocytopenia - antivenom plus supportive care. Scorpion stings in children cause cranial nerve and autonomic storming. Black widow envenomation causes regional pain and muscle rigidity; calcium gluconate and antivenom are options. Jellyfish stings are treated with hot water or seawater, not fresh water.
Rule of thumb: a delayed gastrointestinal illness after eating mushrooms should be treated as amatoxin poisoning until proven otherwise.