Total Body Rash and Fever in Previously Healthy Man: Your Dx?

Figure (click image to enlarge)

You are seeing your last patient of the day when your partner 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. He denies any cough, sore throat, or runny nose as well as any vomiting, photophobia, or diarrhea. He has never had a rash like this before. His symptoms all wax and wane, and have been present for 3 days.

His past medical history is notable only for high cholesterol, for which he has taken simvastatin for many years. He has been taking acetaminophen for his fevers, which have been as high as 103.1^oF. He does not smoke or use recreational drugs, but drinks socially and travels frequently for work.

On physical exam, he is non-toxic. His vital signs are normal, except for an oral temperature of 101.8^oF. His eyes and oropharynx are clear, as are his lungs. He has no neck stiffness or photophobia and his neurologic exam is normal. The rest of his exam is unremarkable except for the rash, which is all over his body (Figure).

His CBC count and metabolic panel are normal; his white count is 1.7/uL.

You ask the patient one question, which your partner had not asked, and nail the diagnosis.

What is the differential diagnosis? 

What was the question? (Hint: The question is not part of the past medical history or review of systems.)

What is the diagnosis?

Please click here for the answers and discussion.