Gangrene induced by methysergide and ergotamine. A case report.

Outbreaks of ergot poisoning (St Anthony’s fire) have occurred in Europe for centuries, the most recent being in 1 953. Ergot is the product of a parasitic fungus infecting grain, in particular rye, and has been recognised as the cause of St Anthony’s fire since the Middle Ages. However, it was not until 1920 that the amino-acid alkaloid, ergotamine, was isolated by Stoll. Ergotamine can reproduce the peripheral vasoconstriction and gangrene which is a prominent feature of ergot poisoning; it is used therapeutically in cases of migraine to reduce the vasodilatation and excessive pulsation of the branches of the external carotid artery. All the alkaloids of ergot are derivatives of lysergic acid, and several types of semisynthetic products have been produced, of which methysergide is one. It is a potent antagonist of 5-hydroxytryptamine, which has been incriminated in the aetiology of migraine. Although methysergide is of established value in the prophylaxis of migraine it has a number of side-effects, the most serious of which is inflammatory fibrosis of retroperitoneal and endocardial tissues.