WBR239

Author	[[PageAuthor::Gerald Chi (Reviewed by Yazan Daaboul, M.D.)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pharmacology, MainCategory::Physiology
Sub Category	SubCategory::Cardiology
Prompt	[[Prompt::A 35-year-old man with no past medical history presents to the clinic with acute-onset, recurrent headaches for the past 3 weeks. The patient states that his symptoms are strongest at the beginning of each business week and usually improve by Fridays and the weekends. The patient denies any allergies or intake of any medications. Upon further questioning, the patient also reports occasional fatigue and light-headedness. In the clinic, the patient's vital signs are within normal limits, and his physical examination is unremarkable. Following history-taking and physical examination, the physician suspects that the patient's symptoms are caused by an occupational exposure. Which of the following industries does the patient most likely work in?]]
Answer A	AnswerA::Steel mill
Answer A Explanation	AnswerAExp::Working in the steel mill may be associated with iron poisoning.
Answer B	AnswerB::Vintage paint manufacturing
Answer B Explanation	AnswerBExp::Vintage paint manufacturing may be associated with lead poisoning.
Answer C	AnswerC::Pesticide manufacturing
Answer C Explanation	AnswerCExp::Pesticide manufacturing may be associated with organophosphate poisoning.
Answer D	AnswerD::Explosive manufacturing
Answer D Explanation	AnswerDExp::Explosive manufacturing may be associated with nitroglycerin exposure, intoxication, and tolerance.
Answer E	AnswerE::Cyanide processing
Answer E Explanation	AnswerEExp::Cyanide processing may be associated with cyanide poisoning.
Right Answer	RightAnswer::D
Explanation	[[Explanation::Monday disease is a form of nitrate tolerance that occurs among individuals who are exposed to high concentrations of organic nitrates, such as those who work in the manufacture of explosives, fireworks, and fertilizers. While healthy individuals may report clinical manifestations related to either the mechanism of action of nitrates (venodilation), such as light-headedness and fatigue, some may experience adverse reactions related to nitro exposure, such as severe, violent headaches. In contrast, patients with angina pectoris often report improved symptoms during the weekdays and recurring chest pains during the weekends. Workers are often exposed to nitrates during the weekdays, developing tolerance to the effects of nitrates. However, the tolerance effect is lost over the weekend, and patients typically re-experience symptoms the next Monday. The discovery of nitroglycerin tolerance was originally attributed to the observations of Monday disease among workers with occupational exposure. Educational Objective: Monday disease is a form of nitrate tolerance that occurs among individuals who are exposed to high concentrations of organic nitrates, such as those who work in the manufacture of explosives, fireworks, and fertilizers. References: Ferreira JCB, Mochly-Rosen D. Nitroglycerin use in myocardial infarction patients: risks and benefits. Circ J. 2012;76(1):15-21. Mayer B, Beretta M. The enigma of nitroglycerin bioactivation and nitrate tolerance: news, views and troubles. Br J Pharmacol. 2008;155:170-84.]]
Approved	Approved::Yes
Keyword	WBRKeyword::Monday disease, WBRKeyword::Nitroglycerin, WBRKeyword::Nitrates, WBRKeyword::Occupational Exposure, WBRKeyword::Explosive manufacture, WBRKeyword::Fertilizers, WBRKeyword::Fireworks
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