Toxicology of fungi: Ergotism due to Claviceps purpurea (ergot) is associated with several clinical effects. Which of the following historical events or effects is NOT caused by ergotism?

Introduction / Context:
Ergot alkaloids produced by Claviceps purpurea contaminate rye and other grains. Understanding their clinical and historical impact distinguishes ergotism from other famine-related plant pathogens.

Given Data / Assumptions:

• Ergot alkaloids cause vasoconstriction, paresthesias, gangrene, and neuropsychiatric symptoms including hallucinations.
• The Irish potato famine (1840s) was caused by the oomycete Phytophthora infestans, not ergot.
• Ergot has obstetric and vascular effects.

Concept / Approach:
Map each item to known ergot effects. Hallucinations and gangrene are classic ergotism manifestations; uterine contractions are pharmacologic effects of certain alkaloids. The Irish potato famine relates to late blight of potato, not ergot.

Step-by-Step Solution:
List known ergot clinical effects (vasospasm, gangrene, hallucinations). Identify unrelated historical event (potato famine due to Phytophthora). Select the “not caused by ergotism” option. Answer: Irish potato famine.

Verification / Alternative check:
Mycology and plant pathology sources consistently attribute the Irish famine to late blight; ergot primarily affects grains like rye, not potatoes.

Why Other Options Are Wrong:

• Hallucinations/Gangrene: Directly linked to ergot toxicity.
• Uterine contractions and vasospasm: Pharmacologic effects of ergot alkaloids.
• Both (a) and (b): Incorrect since (a) is true for ergotism.

Common Pitfalls:
Confusing different historical plant epidemics and their causal agents.

Final Answer:
Irish potato famine.