By Dr Claire Asher

Published: Thursday, 22 December 2022 at 12:00 am


Holy fire disease, also known as St Anthony’s fire or ergotism, is a medical condition that causes a burning sensation in the limbs and, if left untreated, can cause gangrene (tissue death) and seizures. It is caused by eating cereal grains such as rye that have been infected by the purple club-headed fungus Claviceps purpurea.

The fungus releases alkaloid substances into the grains, which stimulate serotonin, dopamine and epinephrine hormone receptors when consumed, making blood vessels constrict. This reduces blood flow to the organs and limbs, causing tissues to die.

The earliest historical references to the disease date back to 857 AD, but its cause wasn’t identified until the 17th Century. By the late 19th Century, agricultural practices, put in place to prevent the fungal infection and remove infected grains, had almost entirely eliminated the disease in humans.

As early as the 1500s, midwifes realised that consuming grains infected by the ergot fungus could induce labour in pregnant women, and by the 1750s, they were stocked by pharmacies as a treatment for stalled labour. However, consuming infected grains made it difficult to give precise doses and the practice became associated with stillbirths. The active ingredient – ergometrine – was purified in 1935 allowing for the medicine to be prescribed more precisely and it remained a popular method for inducing labour, until it was replaced by safer alternatives like oxytocin.

Today, ergometrine is still used medically to prevent bleeding after childbirth, as well as to treat severe migraine headaches. In rare cases, these ergot-based medicines can cause Holy fire disease, especially if the drug is combined with other medications. For example, a case of ergotism was reported in 2020 as a result of combining an ergometrine migraine treatment with HIV medication, causing ergometrine to build up in the body to dangerous levels.

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Asked by: Jenny Warwick, via email

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