Ergotism is a condition caused by consuming grains, particularly rye, contaminated with the fungus Claviceps purpurea. This fungus produces toxic compounds called alkaloids, which can lead to severe health issues. Symptoms of ergotism include hallucinations, convulsions, and gangrene, which can result in tissue death. Historically, ergotism was often referred to as "St. Anthony's Fire" due to the burning sensations experienced by those affected. It was notably prevalent in the Middle Ages, where outbreaks were linked to contaminated bread. Understanding ergotism has helped improve food safety and prevent similar health crises in modern times.