B.C. doctor warns against deadly mushroom that looks similar to edible variety

VANCOUVER — A critical care doctor is warning British Columbians about a “sinister” deadly mushroom and the importance of health-care providers recognizing signs of poisoning from a variety that is spreading along the Pacific coast.

Dr. Omar Ahmad, head of critical care and emergency medicine for Island Health, said the so-called death cap mushroom can easily be mistaken for edible varieties and is responsible for 90 per cent of the world’s mushroom-related fatalities.

A three-year-old boy died in 2016 after consuming a mushroom foraged from a residential street in Victoria. In 2008, a 63-year-old woman who ate a death cap in Vancouver recovered in hospital, and five years earlier, a 43-year-old man was hospitalized in Victoria.

People who eat death caps can experience abdominal pain, vomiting and diarrhea within six to 12 hours, but a false recovery phase follows up to three days later and can prevent people from seeking medical help as toxins attack the liver and possibly the kidneys in a “sinister manner,” Ahmad said.

“That’s really quite a dangerous period with that false reassurance with clinicians as well as patients because that’s when things are happening and it really is the time when we should be intervening and try to prevent further damage,” he said, adding a liver transplant may be the only treatment for people who don’t reach a critical stage.

While patients may think they’ve had the flu or food poisoning, liver damage could progress before convulsions occur and lead to coma and death from the mushroom, Ahman said.

The mushroom was first spotted in the Fraser Valley east of Vancouver in 1997 and Victoria the following year but it also grows in Atlantic Canada.

One mushroom cap is enough to kill an adult but just a small amount is toxic for a child, he said, adding the health authority has been educating doctors through seminars and he has co-authored an article in the BC Medical Journal.