Chronic Ergotamine Use Leading to Peripheral Vascular Disease: A Rare Cause of Acute Lower Limb Ischemia

Acute limb ischemia is usually caused by atherosclerotic or embolic disease; however, drug-induced vasospasm is an important but often overlooked differential diagnosis. Chronic ergot toxicity is a rare cause of lower extremity ischemia. A 54-year-old female with hypothyroidism presented with sudden-onset pain, sensory loss, and weakness of the left lower limb, with a preceding history of bilateral claudication. Computed tomography angiography showed diffuse tapering of the major lower limb vessels. Detailed pharmacological history revealed daily ergotamine use for migraine for 15 years. A diagnosis of ergotamine-induced peripheral vasospasm was made. The drug was gradually withdrawn, and ischemia was managed conservatively with medical therapies. The patient showed progressive improvement and remained asymptomatic at 1-year follow-up. This case emphasizes the importance of meticulous drug history, which helps in identifying reversible causes of limb ischemia and avoids unnecessary interventions.