Mushroom Poisoning

Since the 1970s, the United States has seen a marked increase in mushroom poisoning due to an increase in the popularity of natural foods, the use of mushrooms as recreational hallucinogens, and the gourmet qualities of wild mushrooms. About 90 percent of the deaths due to mushroom poisoning in the United States and western Europe result from eating a type of mushroom known as the Amanita phalloides. Higher death rates of more than 50 percent occur in children less than 10 years of age.

Out of the more than 5,000 varieties of mushrooms found in the United States, about 100 are toxic—and most of these cause only mild stomach problems. A few, however, can cause fatal reactions. Most of the toxic symptoms are caused by the stomach irritants that lead to the vomiting and diarrhea common in mushroom poisoning. In most cases onset of symptoms is rapid, but if the onset is delayed past six to 12 hours, the more serious toxins may be suspected.

Although only an expert can tell for sure if a mushroom is poisonous by looking at it, in general mushrooms growing in the ground are more dangerous than mushrooms growing on living trees, and mushrooms on the forest floor are usually more dangerous than mushrooms on lawns. Since the first report of mushroom poisoning in 1871, much of the information about poisonous mushrooms is inaccurate—including the persistent belief that there are some ironclad “rules” that can be used to tell the difference between edible and toxic varieties. In fact, there is no rule that applies equally to all species. For example, it is not true that a silver spoon or coin put in a pan with cooking mushrooms will turn black if the mushrooms are poisonous. All mushrooms will discolor silver in boiling water, if they are rotten, but no mushroom ever does as long as it is fresh. Toxic mushrooms will not get darker if soaked in water, nor will they get milky if soaked in vinegar.

Symptoms
The most common symptoms of mushroom poisoning include nausea, stomach cramps, vomiting, and watery or bloody diarrhea.

Treatment
There is no specific antidote for mushroom poisoning, but several advances in treatment have lowered the death rate over the last several years. Early replacement of lost body fluids has been a major factor in improving survival rates. The following list outlines what to do if a child accidentally ingests a toxic mushroom:

1. An adult should collect the mushrooms the child was eating; if possible, a few should be dug up so that even the underground parts can be saved for identification. If there are several kinds of mushrooms around the child, all of the different kinds that the child might have eaten should be collected.
2. An adult should check with the child’s doctor, the local poison control center, or the hospital emergency room. If directed to go to the emergency room, the adult should bring the child and the mushrooms.
3. Therapy is aimed at decreasing the amount of toxin in the body. If the child is alert and has not vomited, the adult might be told to administer syrup of ipecac: The child is first given several glasses of water or clear juice to drink, followed by ipecac (one teaspoon to an infant, one tablespoon to children one to 12 years of age, and two tablespoons to children over 12 years of age).
4. The child should throw up everything in the stomach very soon after taking the ipecac. If nothing happens within 20 minutes, the same ipecac dose should be given again.
5. The doctor will check the child’s vital signs and consult a local mushroom expert to determine whether or not the mushroom is poisonous and whether any other treatment is necessary.

Once the toxins have been removed, either by vomiting or by stomach pumping, the doctor will probably order continuous aspiration of the upper portion of the small intestine through a nasogastric tube with oral charcoal every four hours for 48 hours to prevent the toxin from being absorbed. This method works best if started within six hours of ingestion.

In the United States, early removal of mushroom poison by using dialysis and correcting any electrolyte imbalance has become part of the treatment program. An enzyme called thioctic acid and corticosteroids also appear to be helpful, as well as high doses of penicillin.