Answer Case 1
You are correct!
The answer is D. Post infectious cough is most likely.
The multiple choices were: A. Asthma presenting as cough, B. GERD, C. Upper airway cough syndrome, D. Post-infectious cough, E. Bronchiectasis
Explanation: In otherwise healthy young non-smoking adults who don’t take a cough inducing medication such as an ACE, the commonest causes of cough are divided into 3 categories –acute, subacute, and chronic—as follows.
Acute (less than 3 weeks): A viral upper respiratory infection (URI)
Subacute (3-8 weeks): Post-infectious cough following a viral URI
Chronic (more than 8 weeks, in order of frequency): Upper Airway Cough Syndrome (similar to post-nasal drip) > Asthma > GERD
In case 1 the young otherwise healthy patient with a normal physical exam has a subacute cough (4 weeks) which is therefore likely to be post-infectious.
Bottom line: In an otherwise healthy low-risk patient with a persistent cough and a normal exam, duration is an important clue to diagnosis. Algorithms have been developed for treatment that include medications such as anti-histamine-decongestant combinations, nasal and inhaled steroids, PPIs, ipatropium, and cough suppressants such as dextromethorphine and codeine.