What Is Ergotism?

Medically Reviewed by Neha Pathak, MD on October 28, 2022
4 min read

Ergotism, or ergot poisoning, is when a person or animal eats food that has been contaminated with a fungus called C. purpurea. The fungus is most commonly found in rye, but it can affect other grains and grasses, too.

When humans get ergotism, it's also called St. Anthony's fire or holy fire. These names refer to the severity of symptoms, such as burning sensations in your arms and legs. The way people acted when they were poisoned has been associated with witchcraft in the past. Today, we understand that the fungus is responsible for the sometimes gruesome symptoms and change in behavior.

There are two forms of ergotism:

Gangrene. This is when hands, feet, and whole limbs can swell and fall off.

Convulsions. This is when a person sees things that aren't there (hallucinations) and has muscle spasms, rigid flexed limbs, severe diarrhea, and other symptoms.




A plant gets infected when fungal spores land on the grain. The spores form a yellow, sticky substance near the seeds at the top of the plant. An ergot, or sclerotium, replaces the plant's infected ovary. It creates a black- and purple-colored growth, which you can see without a microscope. The cycle continues because it can fall on the ground and continue growing.

Though ergot is dangerous, it has certain chemicals that are used to make prescription medicine.



Symptoms may begin within an hour of ergot poisoning. They can last about a week and get worse if you eat more of the grain that contains the fungus or take more medicine made from it.

Symptoms can include:

  • Headache
  • Nausea
  • Weakness
  • Vomiting
  • Diarrhea
  • Stomach trouble
  • Salivating a lot
  • Excessive sweating
  • Being thirsty
  • Smelly poop
  • Change in appetite
  • Burning pain in skin
  • Cold, pale skin
  • Crawling sensations in the skin
  • Difficulty speaking
  • Ringing in ears
  • Temporary blindness or poor sight
  • Loss of menstrual cycle
  • Pregnancy loss

The fungus is still around, but infections and outbreaks from it are far less common. That's because our farming practices have gotten better. Today’s farmers know to look for it and they know how to remove it. Or they just don’t use affected plants. Removing the fungus from the grain before it's used can be expensive. It can also leave behind toxic residue.

Severe ergot epidemics hit France between 900 AD and 1300 AD, killing up to 50,000 people. There are notable cases all throughout history. Some people believe ergot poisoning is responsible for historical accounts of people being put under spells. The fungus contains highly poisonous and psychoactive alkaloids, including lysergic acid (LSD). LSD is a hallucinogen, which means it changes the way you think and see your surroundings. If a person was acting strange and had "weird" symptoms, some people thought they were practicing witchcraft or put under a spell by it.

Historians suspect it’s why so many people were killed for being witches in Europe during the Dark Ages. The same goes for people in the U.S. killed during the Salem witch trials. Experts say the people weren't possessed or under a spell. They just had signs of ergot poisoning.

Farming practices have improved, but people can also get ergotism from taking medications made from ergot. This is more likely to happen if you take too much of the medication in a short period of time.


The fungus contains alkaloids, which are compounds that have nitrogen in them. Two compounds in the alkaloids are useful in some of today’s medicines: amino alcohol and peptides. Those compounds are used in ergot alkaloid medications like ergotamine and dihydroergotamine, which doctors use to treat headaches that don’t respond to other medications. But taking one of these medicines isn’t a popular choice because people know ergotism is a risk. Ergometrine is another medicine containing ergot. It can be used to stop bleeding after giving birth.

If you’re on these medications, pay careful attention to the dosing. The ergot alkaloids can build up in your body if you take too much in a short period of time. This can lead to gangrenous ergotism. Purified alkaloids don’t cause convulsive ergotism.


Most people recover from the condition in a few weeks or months. Your doctor may do a physical exam and order blood work. They may run scans like an arteriogram, which is an X-ray of your blood vessels. This is to see if they are narrowing, which affects the flow of blood in your body.

Your doctor will stop you from taking any medicines that contain ergot alkaloids. They may give you intravenous or intra-arterial infusion of medicines that relax blood vessels (like sodium nitroprusside or nitroglycerin) to treat ergotism.

Animals usually recover on their own after they stop eating the poisoned food source.