Deadly
Amatoxin poisoning
Amanitin, a cyclic peptide that shuts down RNA polymerase II
Onset after the meal
6 to 24 hours, and the delay is the killer
Later than six hours, which is the line that matters. A delayed onset means an organ is already being attacked, and it is an emergency even if the person feels well by the time they are seen.
Attacks
The liver, and then the kidneys
What it does
Phase one: violent vomiting and cholera-like diarrhoea, 6 to 24 hours after the meal. Phase two: an apparent RECOVERY lasting a day or two, during which people are sometimes discharged from hospital. Phase three: liver failure, jaundice, bleeding, coma.
How it runs
Responsible for the great majority of fatal mushroom poisonings worldwide. Roughly 10 to 20 per cent of cases are fatal even with modern intensive care, and some survivors need a liver transplant.
Treatment
Hospital, immediately, and say the word amatoxin. Intravenous fluids, silibinin where available, high-dose penicillin, N-acetylcysteine, and transplant assessment. Time is everything and there is no home management of this.
The catch
The false recovery is the reason people die. Anyone who ate wild mushrooms and became ill the NEXT DAY needs a hospital, however well they feel by the time they get there. Cooking, drying and freezing do nothing to the toxin.
Species that cause it
This is reference material, not clinical guidance and not a substitute for a poison centre. If somebody is unwell after eating a wild mushroom, call one now, tell them the interval between the meal and the first symptom, and keep an uncooked specimen.