RISK WITH THE UNKNOWN: MUSHROOM POISONING

by Shiva Devkota

Mushroom poisoning is caused by consumption of raw or cooked fruiting bodies of a number of species of higher fungi that have been collected by nonspecialists (although specialists have also been poisoned). Most cases occur when toxic species are confused with edible species. Amanita species appropriately called "death caps," accounts for the majority of cases. Mushrooms poisoning cases in different parts of Nepal are also mostly by Amanita species.The toxins initially cause severe abdominal cramping, vomiting, and watery diarrhea, and then lead to liver and kidney failure.

Nevertheless, mushrooms are reputed to have claimed the lives of a number of historical figures, including Pope Clement VII, King Charles VI of France. One of the most celebrated casualties was the Roman Emperor Claudius Caesar. The highest reported incidences of mushroom poisoning occur in Western Europe. About 90% of the deaths due to mushroom poisoning in the world result from eating Amanita species. More than 50% mortality rates occur in children of less than 10 years. In Nepal, the mortality rate due to consumption of poisonous mushrooms had been found to occur around 15-20 annually. But this result seems to be different in this year because of the higher number of poisoning cases. Last year tragic in Palpa due to mushroom poisoning was also due to the consumption of Amanita species.

Photo: Poisonous mushrooms, vicitims (two ladies), Researcher (Morten Christensen, Denmark) and myself in Srinagar, Tansen, Palpa

Causes and symptoms

Mushroom poisonings are generally acute and are manifested by a variety of symptoms and prognoses, depending on the amount and species consumed. Because the chemistry of many of the mushroom toxins (especially the less deadly ones) is still unknown and actual identification of the mushrooms is often difficult or impossible. Mushroom poisonings are generally categorized by their physiological effects. Poisonous mushrooms contain at least two different types of toxins, each of which can cause death if taken in large enough quantities. Some of the toxins found in poisonous mushrooms are among the most potent ever discovered. One group of poisons, known as amatoxins, blocks the production of DNA, the basis of cell reproduction. This leads to the death of many cells, especially those that reproduce frequently such as in the liver, intestines, and kidney. Other mushroom poisons affect the proteins needed for muscle contraction, and therefore reduce the ability of certain muscle groups to perform.

Symptoms of Amanita poisoning occur in different stages or phases. These include:

First stage is a latency period of 6 to 24 hours after ingestion, in which the toxins are actively destroying the victim's kidneys and liver, but the victim experiences no discomfort.

Second stage is a period of about 24 hours characterized by violent vomiting, bloody diarrhea, and severe abdominal cramps.

Third stage is a period of 24 hours during which the victim appears to recover (if hospitalized, the patient is sometimes released!)

Fourth stage is a relapse, during which kidney and liver failure often occurs, leading to death. There may be more than one relapse.

If you have any reason to suspect that someone has ingested an amanitin-containing mushroom, Don't wait for Symptoms to appear! There is no antidote for amanitin poisoning, and the best hope is to rush the person to the hospital where the toxins can be removed before being fully absorbed into the body. Treatment is largely supportive and symptomatic. Penicillin, kutkin, and silibinin/silymarin show promise as treatments, along with oral activated charcoal and electrolytes.

Diagnosis

In most cases, the fact that the patient has recently eaten wild mushrooms is the clue to the cause of symptoms. Moreover, the identification of any remaining mushrooms by a qualified mushroom specialist (mycologist) can be a key to diagnosis. When in doubt, the toxin known as alpha-amantin can be found in the blood, urine, or stomach contents of an individual who has ingested poisonous Amanita mushrooms.

Treatment

It is important to remember that there is no specific antidote for mushroom poisoning. However, several advances in therapy have decreased the death rate over the last several years. Early replacement of lost body fluids has been a major factor in improving survival rates.

Therapy is aimed at decreasing the amount of toxin in the body. Initially, attempts are made to remove toxins from the upper gastrointestinal tract by inducing vomiting or by gastric ravage (stomach pumping). After that continuous aspiration of the upper portion of the small intestine through a nasogastric tube is done and oral charcoal (every four hours for 48 hours) is given to prevent absorption of toxin. These measures work best if started within six hours of ingestion. In the United States, early removal of mushroom poison by way of an artificial kidney machine (dialysis) has become part of the treatment program. An enzyme called thioctic acid and corticosteroids also appear to be beneficial, as well as high doses of penicillin. When liver failure develops, liver transplantation may be the only treatment option.

Prevention

Only way to avoid poisoning is to avoid consumption of unknown species. There is no general rule of thumb for distinguishing edible and poisonous mushrooms. It is also important to remember that most mushroom poisons are not destroyed or deactivated by cooking, canning, freezing, drying, or other means of food preparation.