A 21 yo college student schedules an appointment at the university health service because of a dry cough for the past 4 weeks. The cough occurs about every 15 minutes and sometimes awakens him from sleep. Prior to the onset of the cough he had a “cold” characterized by a runny nose, sneezing, and sore throat that lasted about a week. He has not had a fever or any other respiratory or general symptoms. His health is good and he does not take any medication. He is majoring in English literature and has not been exposed to animals, dust, fumes, or an ill person. On physical exam his vital signs are normal with temp 98 degrees. HEENT and neck are normal. Palpation, percussion, and auscultation of breath and vocal sounds of the posterior, lateral and anterior chest are negative. Palpation and auscultation of the heart are normal.
Which of the following is the most likely diagnosis?
A. Asthma presenting as cough
C. Upper airway cough syndrome
D. Post-infectious cough