Agency for Toxic Substances and Disease Registry 
Case Studies in Environmental Medicine (CSEM) 

Taking an Exposure History
Initial Check

Instructions

This Initial Check will help you assess your current knowledge about taking an exposure history. To take the Initial Check, read the case below, and then answer the questions that follow.

Case Study

On Tuesday afternoon, a 52-year-old man with previously diagnosed coronary artery disease controlled by nitroglycerin describes episodes of recurring headache for the past three weeks. Mild nausea often accompanies the headache; there is no vomiting. He describes a dull frontal ache that is not relieved by aspirin. The patient states that the headaches are sometimes severe; at other times they are a nagging annoyance. The durations range from half an hour to a full day.

His visit was also prompted by a mild angina attack that he suffered this past weekend shortly after he awoke on Sunday morning. He has experienced no further cardiac symptoms since that episode.

History of previous illness indicates that the patient was diagnosed with angina pectoris three years ago. He has been taking 0.4 milligrams (mg) nitroglycerin sublingually prophylactically before vigorous exercise. He also takes one aspirin every other day. He has been symptom-free for the past 2½ years.

Sublingual nitroglycerin relieved the pain of the Sunday morning angina attack within several minutes.

The patient does not smoke and rarely drinks alcohol. He is a trim man with a slightly ruddy complexion.

At present, he is afebrile, and his vital signs are as follows

• blood pressure 120/85
• pulse 80
• respirations 20

Physical exam is normal.

The results of an electrocardiogram (ECG) with a rhythm strip performed in your office are unremarkable.

Subsequent laboratory testing reveals normal blood lipids, cardiac enzymes, complete blood cell count (CBC), sedimentation rate, glucose, creatinine, and thyroid function.

Initial Check Questions

1. What would you include in the patient’s problem list?
2. What would you include in the differential diagnosis?
3. What additional information would you seek to assist in the diagnosis?

Initial Check Answers

1. The patient’s problem list includes recurrent headache and nausea, and unstable angina pectoris.
2. The patient’s differential diagnosis of chest pain includes myocardial infarction. The differential diagnosis of headache and nausea includes viral syndrome, tension headaches, migraine, brain tumor, tooth or sinus problems, psychogenic headache, medication reaction (nitroglycerin can cause headaches), and exposure to toxicants (carbon monoxide, solvents).
3. The additional information sought to make a diagnosis would include all aspects of a work and environmental exposure history.