Karen Brown, M.D.
1. Clarify definition of “chronic” cough
2. List most common etiologies
3. Develop diagnostic strategy to diagnose and treat chronic cough
Mrs. Annie Tussif, a 38-year-old new patient, presents with a cough that she has noticed for
four weeks. She describes the cough as hacking, with coughing “spells” that can last up to
five minutes and causes her embarrassment in meetings and interrupts her sleep. She has
never had any similar problems, has no sick contacts, and is otherwise very healthy.
Guaifenesin (Robitussin) is not helping enough.
1. Does she meet criteria for chronic cough?
Because her cough is lasting between three and eight week,s it is classified as subacute
rather than chronic cough.
2. What are the most common underlying causes of her cough?
The most common cause of subacute cough is bacterial sinusitis or asthma (e.g. cough
variant asthma). It is also commonly post-infectious. Finally, a subacute cough may be
the new onset of what will become a chronic cough. The most common causes of chronic
cough are listed on the second page of the article and, also, later in this answer key.
3. What further history and exam findings are necessary to complete her evaluation
History of recent viral illness, presence of sinusitis symptoms such as fever, facial
pressure, or purulent nasal drainage. History of any prior episodes or family history of
asthma. GERD sx? Occupational and environmental history with focus on airway
irritants (bleach, paint fumes, cigarette smoke) or allergens (dust, red cedar, animals).
CASE ONE CONTINUED:
Upon further history you learn that she has no chronic medical problems, does not take
any medications daily, has longstanding environmental allergies, and cleans houses for a
living. She has occasional symptoms of heartburn. She does not smoke, does not drink
alcohol, and does not use any nonprescription or illicit medications. She recalls that the
cough started during an upper respiratory illness, but has simply not resolved. Her
examination is normal except for a slight wheeze in one lung field.
4. How would you proceed in order to complete the visit?
Testing is not likely indicated. The most likely etiology is a post-infectious cough.
If there were ongoing fevers or generalized fatigue then a CXR would be
indicated to look for “walking” (e.g. atypical) pneumonia. If she were a smoker
or had high-risk occupational exposure, this would also be indicated.
While the cough will almost certainly resolve on its own, both bronchodilators
and steroid inhalers can be used to treat a post-infectious cough (in addition to
the cough syrup). If these episodes occurred frequently then cough variant
asthma should be considered.
Exposure to airway irritants can delay healing of her airway and prolong the
cough. In this case the cleaning solutions may be perpetuating the cough. She
should be advised to avoid airway irritants as much as possible.
CASE ONE CONTINUED:
She returns six weeks later and reports NO improvement in her cough with the inhalers
that you prescribed. She continues to have coughing spells 4-5 times daily and now
confides that her cough is so severe that she is suffering from urinary incontinence as well.
Her examination is normal.
5. What are the most common causes of chronic cough?
Post-nasal drip syndrome, asthma, and GERD are the most common causes of chronic
cough in patients who do not take ACE inhibitors and have a normal CXR. Often one
patient has two or more of these causes.
ACE inhibitors induce cough in 5-20% of patients who take them, and it can begin
several months after the initiation of the medication. The cough SHOULD subside within
a few days of stopping the medication or switching to ARB.
6. Outline a diagnostic strategy. Review the one presented in the reference article. Do
you agree with their sequential approach?
Clearly CXR is now indicated. As long as the CXR is normal, this article recommends
sequential two-week trials of treatment for the three common causes of chronic cough.
Assuming that she can demonstrate adequate meter dose inhaler technique, you have
already completed a trial of asthma treatment. This algorithm differs from some others
in that the response to therapeutic interventions is accepted as diagnostic of the
underlying disorder. For example, an alternative approach might be to test for asthma
using PFTs (even methacholine challenge), to test for GERD using 24-hour pH probe,
and to refer for ENT evaluation. The other main difference from other articles is the lack
of empiric course of antibiotics (usually azithro/doxy/erythro) early in the algorithm to
treat tracheobronchitis. This approach seems to be endorsed by the American College of
Chest Physicians. Make sure to point out the necessity for CXR in this algorithm. Other
causes of cough such as sarcoid, pneumonia, TB, interstitial lung disease, mesothelioma,
and lung cancer need to be excluded as they are not that rare. Also, point out that this
algorithm is for immunocompetent patients only.
7. How would you proceed in order to complete the visit?
You can try nasal steroids for post-nasal drip if there is evidence on exam
(cobblestone posterior pharynx or throat clearing). Note that the drip may be
clinically “silent”. Could also try PPI for GERD. The GERD can be causing a
cough or frank asthma without typical heartburn symptoms. According to the
article one should prescribe a two-week trial of each to determine which works.
CASE ONE CONTINUED:
She returns five months later for an annual physical. She has no new medical concerns,
but is most interested in discussing bone density, mammography, and immunizations
today. When you inquire about her cough she replies “Oh yes, the cough. I had almost
forgotten—it’s gone.” She is no longer taking any prescribed medications.
8. Would you recommend restarting medications at this point?
9. If she hadn’t stopped them on her own, would you have advised her to discontinue
medications now that her cough has been resolved for four months?
Yes—an irritated airway can heal.
1. Holmes R.L. and Fadden C.T. Evaluation of the patient with chronic cough. American
Family Physician. 2004; 69(9):2159-2166.