Kaplan USMLE Step 2: Patient says his skin is crawling

If you’re preparing for the United States Medical Licensing Examination® (USMLE®) Step 2 exam, you might want to know which questions are most often missed by test-prep takers. Check out this example from Kaplan Medical, and read an expert explanation of the answer. Also check out all posts in this series.  

A 50-year-old man comes to the emergency department because of bilateral hand tremor, diaphoresis, anxiety, nausea, headache and the sensation that “my skin is crawling.” His medical history is significant for hypertension that is treated with hydrochlorothiazide and enalapril.

He also has bipolar disorder and anxiety, which is treated with three medications prescribed by his psychiatrist. He ran out of these three medications 3 days ago. His temperature is 37.0 ºC (98.6 ºF), blood pressure is 150/100 mm Hg, pulse is 115 beats per minute, and respirations are 20 breaths a minute. Physical examination is notable for diaphoresis and tremulousness.

Administration of which of the following is the most appropriate initial step in this patient's care?

A. Clonidine.

B. Diazepam.

C. Haloperidol.

D. Hydrochlorothiazide.

E. Prochlorperazine.

The correct answer is B.

This patient takes an unknown anti-anxiety medication. Based on his withdrawal symptoms after not taking the medication for three days, it is likely that he has been taking a benzodiazepine. Commonly observed symptoms of benzodiazepine withdrawal include anxiety, diaphoresis, irritability, insomnia, fatigue, headache, myalgia, nausea, perceptual disturbances, tremors and seizures.

The most appropriate management step would be parenteral administration of a benzodiazepine with a prolonged clinical effect, such as diazepam.  

Choices A and D: Clonidine and hydrochlorothiazide are used for the treatment of elevated blood pressure. Both would not be an appropriate initial management choice for this patient because neither would address the underlying cause for his elevated blood pressure, which is benzodiazepine withdrawal.