You are working in a double-covered ED when your colleague asks you for a second opinion on a rash.  The patient is a 43 year old businessman who complains of fever, rash, headaches and body aches, all of which come and go, and have been present for the past 3 days.  The rash, which is all over his body, is shown below.

You ask the patient one question and nail the diagnosis. Of course it helps that your friend recently had the same condition. What is the question? What is the diagnosis? Hint: His only abnormal lab is a white count of 1.7.

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