Mushrooms poison father and son

A Te Aroha man faces a liver transplant and his three-year-old son is in Auckland's Starship Hospital after they ate deadly mushrooms.

The pair, understood to be recent arrivals from Vietnam, had picked death cap mushrooms to cook and eat at their home on Sunday.

Waikato Hospital gastroenterologist Tony Smith said the toddler would be "okay" but his father, aged in his mid-30s, needed a liver transplant.

He was in the critical care unit at Auckland Hospital after being transferred from Waikato Hospital on Tuesday.

Dunedin-based National Poison Centre toxicologist John Fountain, who helped identify the deadly mushroom, said it was toxic to the liver and probably the most poisonous mushroom in New Zealand.

The death cap mushroom -- which can resemble a puffball in its early stages -- was small and brown with a green or brown cap and white gills. It was often found growing close to introduced species of trees such as oaks.

"Obviously the father just did not realise that he had picked a poisonous mushroom," Dr Fountain said.

"I think the take-home message from this is that people really shouldn't go fossicking for mushrooms unless they are very, very good at identifying the particular mushrooms they have picked."

Just one mushroom cap would be enough to cause liver failure in an adult, while one bite could do the same to a child. It could also seriously damage the kidneys.

Dr Fountain said there were one or two cases of death cap poisoning every few years. He had yet to hear of a fatality.

The death cap had a similar appearance to edible fungi found in other countries, he said.

Landcare Research mycologist (mushroom expert) Peter Johnston said when the death cap was young it was easily confused with a puffball, which some people ate.

"Very difficult to tell them apart... you have got to know what you are eating," he said.

Toxins in death caps stopped human cell division, meaning organs which formed new cells, such as the liver, stopped working, Dr Johnston said.

- NZPA