1

COUGH
Learning Objectives
▪ To define and classify different types of cough.
▪ To list the different causes of each type of cough.
▪ To evaluate and manage most common causes of cough.
 3

DEFINITION
Introduction
▪ Cough is an explosive expiration that clears the airways from
secretions and foreign bodies.
▪ It is a frequent symptom related to the respiratory tract.
▪ It is the most common presenting complaint in patients of all
ages to ambulatory clinics.
▪ Every primary care physician will see at least one patient with
cough every day.
Classification
According to the second American College of Chest Physicians
Expert Cough Panel , cough should be classified according to its
duration:
▪ Acute Cough: is a cough of less than 3 weeks duration.
▪ Subacute Cough: is a cough lasting 3 to 8 weeks.
▪ Chronic cough: is a cough of more than 8 weeks duration.
Acute Cough-1
▪ Respiratory infections (mostly viral) are most common causes.
▪ Less common but an important cause of acute cough is the
exacerbation of underlying diseases such as asthma, Chronic
Obstructive Pulmonary Disease (COPD) or pneumonia.
▪ Usually, acute cough doesn’t require any investigations in an
immunocompetent patient.
▪ It is normally self limited.
 Acute Cough-2
▪ When a bronchospasm is the triggering factor, the cough might
persist for weeks after a viral upper respiratory tract infection
(URTI).
▪ Serious causes such as lower respiratory tract infections,
malignancies, pulmonary embolism and congestive heart
failure should be considered in the presence of red flags.
▪ Tuberculosis should be considered in all those presenting for
cough in endemic areas, and in high-risk population such as
immunosuppressed patients, regardless of the duration of
cough and even if chest radiographs are normal.
Subacute Cough
▪ Most common causes are:
o Post infectious cough:
▪ following a respiratory infection, due to postnasal drip
▪ hyperactive airways
o Exacerbation of underlying diseases such as asthma, COPD
and chronic bronchitis.
o Ongoing infectious process, such as Pertussis
▪ The course of subacute cough is often self limited, with post
infectious etiology being a common cause.
▪ When the cough is not clearly related to a post infectious
process, it should be evaluated in the same way as chronic
cough.
Pertussis
▪ When Pertussis is suspected, diagnosis is made by
nasopharyngeal swab culture.
▪ Empirical treatment with a macrolide antibiotics can be started
when the coughing lasts more than 2 weeks, in association with
one of the following:
o An inspiratory whooping sound,
o Paroxysms of cough, and
o Post-tussive emesis.
▪ Close contacts should receive also post exposure prophylaxis
with antibiotics
Chronic Cough
▪ It is hard to estimate the prevalence, with a range of 3 to 40 %.
▪ More common in women in general, namely post menopausal
women.
▪ Obesity, living a polluted environment, gastroesophageal reflux
disease (GERD) and irritable bowel syndrome (IBS) are
considered risk factors for chronic cough.
▪ Coughing for more than 8 weeks is less likely to be the result of
a respiratory infection.
▪ The cough is secondary to more than one pathology in around
half of the cases.
 11

CAUSES OF CHRONIC
COUGH
Causes of Chronic Cough
▪ In nonsmoker patients, those not on ACE Inhibitors, who have
a normal CXR, the cause of the chronic cough is secondary to
the following, either each entity alone or in combination with
each other, in more than 90% of the cases.
o Upper airway cough syndrome
o Asthma
o GERD
o Non-asthmatic eosinophilic bronchitis.
Less Common Causes of Chronic Cough
▪ Bronchiectasis
▪ ACE inhibitors
▪ Bronchogenic carcinoma
▪ Interstitial lung disease
▪ Occult heart failure
▪ Occult aspiration
▪ Occupational asthma
▪ Nasal polyps
▪ Psychogenic
▪ Sarcoidosis, tuberculosis, pertussis.
Upper Airway Cough Syndrome-UACS
▪ It is the most common cause of chronic cough in nonsmokers,
when CXR is normal.
▪ Previously known as postnasal drip syndrome, now it includes
all upper airway abnormalities: allergic and non allergic rhinitis,
and sinusitis.
▪ The most important feature is the feeling of abnormal
sensations, or something stuck in the throat.
▪ The cough is typically dry to minimally productive.
▪ Patients might complain of associated rhinorrhea, nasal
congestion, and postnasal drip.
▪ The absence of the above-mentioned symptoms does not rule
out the diagnosis.
UACS Criteria
▪ The diagnosis is made by the presence of certain criteria:
o Suggestive history and physical exam
o CXR to rule out other causes, and
o a response to a therapeutic trial.

▪ The history should rule out other possible causes to the cough
first, such as medications intake, or pulmonary involvement.
UACS - Physical exam

Classic findings:
▪ wet throat and cobblestone appearance of the oropharynx.
▪ nasal abnormalities, mainly presence of crust, polyps, and
swelling of the mucosa
▪ wheezing on inspiration, coming from the glottis.
UACS - Diagnosis
▪ Findings on physical exam are sensitive but not specific of
UACS.
▪ There is no test that can prove the diagnosis.
▪ When the history and physical exam are supportive of the
diagnosis, and an alternative cause is ruled out, the diagnosis is
confirmed by a good response to an empirical treatment.
▪ Imaging such as CXR or CT of sinuses should be done only if
pneumonia or sinusitis are suspected.
UACS – Management 1
▪ When allergic rhinitis is identified, elimination, if possible, of the
allergens should be attempted. First line treatment is intranasal
steroids.
▪ Cough will improve few days to 2 weeks after starting intranasal
steroids, they should be continued for up to 3 months.
▪ When non allergic rhinitis is suspected, a trial with oral first-
generation antihistamine with or without decongestant should be
considered first. Second generation antihistamine are less effective,
considering their weaker anticholinergic effect. Intranasal Steroids
are also effective for all kind of rhinitis.
▪ The sedative effect of the first generation strongly limit their use.
▪ Intranasal antihistamine and ipratropium bromide could reduce the
rhinorrhea and might improve symptoms.
UACS - Management2
▪ Improvement after 2 weeks of empirical treatment confirms
the diagnosis.
▪ Lack of showing any improvement after 2 weeks is enough to
confirm that the cough is not secondary to UACS.
▪ When the symptoms and signs strongly suggest nasal
symptoms:
o a CT is done to rule out sinusitis as the cause of the cough
and
o adequate treatment will follow.
o Avoiding allergic and environmental triggers is desirable in all
patients
Cough Variant Asthma-1
▪ It is the second most common cause of chronic cough in adults.
▪ Although cough with wheezing and dyspnea point out to
Asthma, isolated cough can be the only symptom of cough
variant asthma. A cough that might be worse at night or
exacerbated by cold weather and exercising.
▪ When the history and physical exam are suggestive, diagnosis is
confirmed by:
o Spirometry
o a therapeutic trial with inhaled corticosteroids and on as needed use of
inhaled bronchodilators.
▪ The best method to confirm that the cough is due to asthma is
to find improvement in the cough when given adequate
treatment for asthma.
Cough Variant Asthma-2
▪ Most patients respond after 1 week of treatment . They
should continue for 8 weeks to expect complete resolution of
the cough.
▪ Oral prednisone can be given for 5 to 10 days :
o When the cough is severe,
o not responding to treatment, and
o if asthma is strongly considered.
GERD Induced Chronic Cough-1
▪ It is the third most common cause of chronic cough in
nonsmokers, with normal Chest X-ray.
▪ The association of chronic cough and GERD has been described
in many studies.
▪ Acid reflux can irritate the respiratory tract, which stimulate the
cough reflex.
▪ The presence of heartburn or a sour taste in the mouth are
clinical clues; These symptoms are present in only one third of
the patients.
▪ Persistent cough could be the only manifestation of the illness.
▪ GERD can exacerbate symptoms of asthma.
GERD Induced Chronic Cough-2
▪ The most accurate method for diagnosis is the Ambulatory
esophageal pH monitoring over a 24-hour period.
o It could be considered inconvenient and not accessible by most patients.
o Its use is very limited
GERD Induced Chronic Cough-3
▪ Although the evidence is not strong and Proton pump
inhibitors have no universal beneficial effect on improving
cough, when GERD induced chronic cough is suspected,
Consensus guidelines recommend:
o The use of PPI empirically for at least 2 months
o Changes in lifestyle including diet and exercise in order to lose
weight.
▪ Symptomatic improvement and resolution of the cough might
take up to 2 months to appear.
▪ Treatment should continue for up to 6 months.
Non asthmatic eosinophilic bronchitis
▪ It is an increasingly diagnosed cause of chronic dry cough, especially
in nonsmokers, not on ACE inhibitors with no red flags.
▪ Patients are usually atopic. The sputum contains elevated level of
eosinophils.
▪ It is characterized with absence of bronchospasm, which
differentiates it from asthma, and thus it shows no response to
bronchodilators.
▪ It typically responds to inhaled steroids which should be given for
four weeks.
▪ When an occupational allergen is the inciting cause, avoidance is very
important.
▪ Oral steroids might be added in case no improvement on inhalers.
ACE inhibitors (ACEI)
▪ ACEI can be associated with chronic cough in 5 to 35% of cases.
▪ Women more than men usually complain of cough secondary
to ACEI.
▪ The cough can start within days to months after the initiation
of the medication, and it is not dose related.
▪ Stop the ACEI: the cough should improve within 1 to 12
weeks.
▪ ACEI can be substituted with ARB’s.
▪ If there is strong indication, the ACEI can be restarted after
resolution of the cough, with low risk of recurrence.
 27

APPROACH TO PATIENTS
WITH CHRONIC COUGH
Evaluation of chronic cough
▪ Chronic cough evaluation is challenging; most of the causes
cannot be determined with accurate diagnostic tests.
▪ Best way to evaluate a chronic cough is:
o By taking a thorough history and looking for typical historical
features.
o By elimination of alternative causes
o By response to therapeutic trials.
▪ Following a systematic approach, cough will resolve in over
90% of cases.
History
A good history should include information about:
▪ Nature of the cough: dry, productive or blood tinged.
▪ Pattern of the cough: duration, frequency, diurnal versus nocturnal,
relation to eating, talking or exercise.
▪ Associated symptoms: wheezing, shortness of breath, presence of
nasal symptoms/ rhinorrhea, congestion, throat irritation, postnasal
drip.
▪ History of atopy, asthma, COPD, allergies.
▪ Smoking history: more than 20 pack years or smoker older than 45
years.
▪ Occupational and environmental factors.
▪ Travel exposures.
▪ Medications including ACE Inhibitors and beta blockers.
Red Flags
▪ A thorough history should be taken to rule out red flags:
o Fever
o Weight loss
o Hemoptysis
o Hoarseness or dysphagia
o Excessive dyspnea
o Purulent sputum production
o History of recurrent pneumonia
o Smoker older than 45 years
o Smoking history of more than 20 pack years.
▪ Presence of red flags needs further exploration with diagnostic tests
to rule out conditions such as malignancies, tuberculosis, heart
failure, fibrotic lung disease etc.
Physical Exam

▪ A complete exam should identify the presence of fever,

clubbing, and/or enlarged lymph nodes, which could
indicate a chronic illness or a malignancy.
▪ Ears, nose and throat exam
▪ Lung exam to look for crepitations, decreased air entry,
wheezing.
Diagnostic Tests
▪ Chest radiography should be obtained in patients with chronic
cough unless a cause has been identified.
▪ When it is normal, it can safely rule out most infectious,
inflammatory and malignant processes.
 33

MANAGEMENT
Acute cough: management 1
▪ The first step in the management is to identify and diagnose the
cause, and to rule out a life-threatening condition, which
necessitates an urgent care.
▪ If the cough is secondary to common cold:
o Home remedies such as honey provide good antitussive effect.
o Over the counter (OTC) medications might contain several ingredients to
target all symptoms of cough, of which, Dextomethorphan, an opiate
derivative, is an antitussive.
o a combination of first-generation antihistamine/ Diphenhydramine, with a
decongestant medications/ phenylephrine, can be used with modest benefit.
▪ Adverse effects of first-generation anti histamine include:
o Arrhythmia, dizziness, dry mouth, hallucinations, respiratory depression, sedation and
urinary retention.
▪ Adverse effects related to the decongestants include:
o Agitation, anorexia, dystonic reactions, headache, hypertension, irritability, nausea,
palpitations and seizure.
▪ These side effects might be more significant in older adults.
Acute cough: management 2
▪ Second generation antihistamine have no effect on cough
secondary to common cold.
▪ Counseling all patients to prevent spread of the infection, and
contagion by hand and by droplets, by encouraging
handwashing and avoidance of social contact.
▪ A routine follow up, in person or by phone call, should occur in
4-6 weeks after the initial evaluation.
▪ In case of persistent symptoms, patients should be educated to
follow up for reassessment.
Management of chronic cough
▪ Studies showed that the clinical approach should not be based
on the patient’s description of the chronic persistent cough
(the character , the timing or whether it is wet or dry cough) as
this information doesn’t help to reach a diagnosis.
▪ It is rather recommended to provide treatment for the most
common causes
o whether sequentially ( the preferable way) OR
o concomitantly in certain cases.
Empirical Therapeutic Trial
▪ Empirical therapeutic trial for the most common causes of
chronic cough should be given.
▪ Start sequentially with UACS, then Asthma, finally GERD, if
there is no typical symptoms that points to one condition more
than the other.
▪ Some patients might have more than one reason for the
cough, which will be in this case, more severe, and will not
improve unless treatment has targeted all causes at the same
time. Once improvement is noticed, treatments can be stopped
one after the other.
Management of chronic cough – step 1
▪ First elements in the history of a patient with chronic cough
should focus on identifying possible triggers:
o Smoking status
o Exposure to irritants in the environment
o ACE inhibitors use

▪ After smoking cessation, irritant avoidance, and

discontinuation of ACE inhibitors, the cough should subside in
2-4 weeks.
Management of chronic cough – step 2
▪ When history rules out red flags and physical exam does not
identify any abnormality
o The management should focus on identifying and treating
the most common causes of chronic cough in adults.
▪ No need for CT of chest or sinuses, nor bronchoscopy
Management of chronic cough – step 3
▪ First, if allergic rhinitis is suspected, start with intranasal steroids to
treat UACS.
▪ If non allergic rhinitis is more likely, start a therapeutic trial with first
generation anti histamine such as Chlorpheniramine, with or without
decongestant.
o First generation antihistamine are preferred over second generation considering
that their anti cholinergic effect has a more favorable effect on the cough, but
their sedating effects limit largely their use, especially in the older patients. The
alternative is to use intranasal steroids, or intranasal anti histamine/ azelastine
for non allergic rhinitis.
▪ If no improvement after 1- 2 weeks of treatment, before excluding
UACS as the reason for the cough, and in the presence of nasal
symptoms or signs: A CT scan of the sinuses should be performed to
rule out sinusitis.
Management of chronic cough – step 4
If UACS is ruled out either by lack of suggestive history and
physical exam, or by lack of improvement after 2 weeks of
therapeutic trial, a cough variant asthma should be considered:
▪ spirometry should be done to demonstrate a reversible
airflow obstruction
▪ Inhaled glucocorticoids and bronchodilators started, and
improvement expected after one to two weeks. Treatment
should continue for at least 3 months
▪ If partial response on medical treatment and spirometry was
not conclusive, consider methacholine challenge test to assess
for bronchial hyperresponsiveness.
▪ When negative, it excludes Asthma.
.
Management of chronic cough – step 5
▪ Next, treat GERD:
▪ Chronic cough from any diagnosis, can precipitate reflux and
induce irritation. This will cause a vicious circle of events which
will perpetuate cough and reflux.
▪ GERD should always be treated at this stage for at least 2
months.
▪ Empirical treatment of proton pump inhibitor (PPI) such as
Omeprazole 40 mg per day should be given.
▪ When no improvement of the cough after 1-2 months of
adding a PPI, 24-hour esophageal pH probe monitoring should
be done.
Management of chronic cough – step 6
If the empiric management fails to show improvement:
▪ Investigations should target the less common causes
▪ Referral to a pulmonary or otolaryngologist should be
considered.
▪ Considering psychogenic cause for the cough should be the
least resort:
o Treatment consists of speech therapy, along with neuromodulators such
as Gabapentin or Pregabalin for at least 4 weeks
References

▪ Michaudet C, Malaty J. Chronic Cough: Evaluation and Management. Am Fam

Physician. 2017; 96(9):575-580.
▪ Silvestri RC, Weinberger SE. Evaluation of subacute and chronic cough in adults. In:
Hollingsworth H, ed. UpToDate, Waltham MA: UpToDate; 2017.
www.uptodate.com.
▪ Weinberger SE, Silvestri RC. Treatment of subacute and chronic cough in adults. In:
Hollingsworth H, ed. UpToDate, Waltham MA: UpToDate; 2018.
www.uptodate.com.