Poisonous Plants and Mushrooms

shutterstock_78360337Traveling out in the wilderness or being in a survival situation can bring people to look for or depend on plants for food/nourishment.  Sometimes these plants can be extremely poisonous and cause illness.

Anything in the correct dose can be poisonous.  “The dose makes the poison.”

I credit the information that I’ve learned and written here to Richard Clark, MD who is medical toxicologist and expert in Wilderness Medicine.

Mushroom ingestion:

It’s difficult even for a trained botanist to identify all mushroom varieties and 95% of the time the type ingested is unknown.  There are less than 100 reported fatalities related to mushroom ingestions in 25 years.  Most patients are treated at home.  Most cases reported to the poison control center were related to children, however all reported deaths were in adults.  Mushroom toxicity varies widely.  Management and prognosis often depend on the history and geographical location of the ingestion as well as the initial signs/symptoms.  The largest and most diverse group are the “little brown mushrooms.”  These are often mistaken for edible varieties.

Symptoms of toxic mushroom ingestion can be classified as early or late.

Early gastrointestinal symptoms may begin in ½ hour to 3 hours after ingestion and may be:

1)  Severe nausea, vomiting and diarrhea
2)  Stools may be bloody
3)  Symptoms may last 6-24 hours
4)  Most of the time no labs are needed, but when symptoms are severe liver enzymes may be monitored

Treatment:  Hydration and anti-nausea medication and possible narcotics for pain.

Mushroom ingestion with late gastrointestinal symptoms:  may begin 6-12 hours after ingestion.

Mainly differentiated between 2 varieties – Amanita/Galerina and Gyromitra.  There are several liver toxic Amanita species:  phalloides, virosa, verna.  They have a greenish color cap and like to live under oak trees.  They are the most common vegetable cause of human death in the USA.  Phase 1: 8-12 hours after ingestion – abdominal pain, vomiting and diarrhea.  Phase 2:  Begins 12-36 hours after ingestion and patients may actually improve.  Phase 3:  2-6 days after ingestion, the patient may get severe liver death and kidney disease.  There are no antidotes available.  Treatment is supportive care and organ transplant if necessary.

Several species may look like a morel (Morchella esculenta) and are the esculenta, infula, ambigua.  These false morel may be edible in some parts of the U.S.  In areas where they are toxic, the toxins may sometimes be destroyed by cooking.  Symptoms including nausea, vomiting, diarrhea seizures and possible liver damage begin 6-12 hours after ingestion. Treatment:  Rehydration, activated charcoal, benzodiazepines, pyridoxine.

Plant induced itchy rash (contact dermatitis):

1)  Poison Ivy
2)  Poison Oak
3)  Poison Sumac

Exposure to mango, pistachio and cashew can also cause the reaction.

50% of the population is highly sensitive.  Oils on plant turn black on contact with air.  These plants are found in all 48 continental states.  P. Ivy is mostly in the eastern states, P. oak is mostly in the west and Sumac is mostly in the southeast.

Severe cases can progress to a severe type 1 hypersensitivity reason.  Symptoms usually begin with 2-4 hours after exposure and may include:

1)  Redness
2)  Itching
3)  Blisters
4)  More severe cases may cause fever, nausea, vomiting, dehydration
5)  Skin infection secondary

Treatment:  prevent severe symptoms by early washing with soap and water (toxin is oily).  Treat with systemic corticosteroids and topical lotions, steroid creams and antihistamines.

There are several products that help prevent exposure to the plants by wearing them – including barrier creams, lotions or sprays – these are poorly protective.  Stoko Gard Outdoor Cream provides great protection if washed off by 8 hours post-exposure.  IvyBlock is another product that can provider good protection.

The “Unknown” Berry Ingestion:  Most of these are non-toxic but can cause gastrointestinal illness.  Large quantities of almost any plant can cause nausea/vomiting.Decontamination with pumping the stomach or charcoal is rarely needed.  Rehydrate and give anti-nausea medicines or benzodiazepines for seizures or agitation.

Holly:  Over 300 species, causes nausea, vomiting and diarrhea.  Treat with rehydration

Pokeweed:  Native to Eastern USA along roads and moist areas.  Rapid onset of severe nausea, vomiting and diarrhea.  Treat with rehydration.

Castor bean:  Grows wild in southern California.  The seed is the most toxic part.  Whole seeds are “nontoxic” except for severe gastroenteritis.  Treat with rehydration.

Jequirity bean:  Native to Florida and the Keys.  The bean is the toxic portion of the plant.  Causes severe nausea, vomiting and diarrhea.  Treat with rehydration.

Ricin and Abrin:  Two of the most toxic substances with the highest concentration in the seeds.  Intoxications result in multisystem organ failure.  Seed coat must be destroyed.  There are few if any reported cases of fatalities when seeds ingested

Water Hemlock (Cowbane, false parsley):  Grows throughout the USA along roads and ditches and is often mistaken for wild carrots or wild parsley.  It was used extensively for suicide in ancient Greece.  Most lethal plant in North America.  Tuberous root.  Causes rapid onset of seizures.  Treat with airway protection and anticonvulsants.

Nicotine:  Found in woodlands and along roads.  Poisoning from touching on the skin, inhalation or gastrointestinal exposure.  Rapid onset of severe nausea, vomiting, diarrhea, headache, dizziness, confusion, seizures and possible coma and paralysis.

Jimson Weed:  Grows along roads and fences throughout the USA.  Seeds are particularly potent.  Mind altering properties noted in ancient literature.  Seeds contain atropine (50-100 seeds may contain 3-6mg).  Anticholinergic toxicity.  Treat with sedation and possibly physostigmine.

Foxglove, Lily of the Valley, Oleanders:  Contain heart glycosides that can lead to stopping of the heart, rapid pulse, or arrhythmias.

Hellebore:  Found in moist woodlands of eastern and western USA.  Used as a sneezing powder.  Can cause nausea, vomiting, low blood pressure, slow heart rate and heart dysrhythmias.

Aconite (Monkshood, wolfsbane):  Can cause cardiotoxicity (dysrhythmias) or neurotoxicity (paresthesias).  Treat with lidocaine and supportive care.

Rhododendron including azaleas and laurels:  Leaves and flowers contain small amount of Andromedotoxin or grayantoxin that can cause cardiac dysrhythmia but there has only been one reported case in the last 20 years.

Unknown plant ingestion with patient having seizures:  Wide differential of plants that cause this.  Symptoms can advance quickly.  Often symptoms begin with nausea and vomiting and can progress to coma and paralysis.

There are many other plants that are toxic.  Please contact your medical provider or your local poison control center.  There are more than 40 nationally certified and they are open 24 hours/day and staffed by specialists in poison information.  There is backup from medical toxicologists.

If you have a poison exposure or question, the poison helpline number is:  1-800-222-1222 and is available 24/7 365 days of the year.  Also, the American Association of Poison Control Centers website has some valuable information as well:  http://www.aapcc.org/dnn/default.aspx

If you are interested in learning more about wilderness medicine, a great resource for information is the wilderness medicine society:  http://www.wms.org/

This document is for informational purposes only, and should not be considered medical advice for any individual patient.  If you have questions please contact your medical provider.


I hope that you have found this information useful.  Wishing you the best of health,

Scott Rennie, DO

Blog: https://doctorrennie.wordpress.com


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