This document discusses the approach to a patient presenting with chronic cough lasting more than 8 weeks. It describes the cough reflex pathway and etiologies of chronic cough, including upper airway cough syndrome, asthma, gastroesophageal reflux disease, non-asthmatic eosinophilic bronchitis, and ACE-inhibitor use. It provides details on diagnosing and managing these conditions through clinical history, examinations, diagnostic tests, and treatment trials. Other potential causes discussed include psychogenic cough and underlying structural lung diseases.

1. Approach to a patient with
Chronic Cough
Presented by-
Dr. Debasish Bhowmick

2.  Usually defined as one lasting more
than 8 weeks.
 Key symptom of many important
chronic respiratory diseases.
 May be the sole presenting feature of
a number of extra-pulmonary
conditions.

3. Cough Reflex: Afferent Pathway
Mechanical stimuli:
– Rapidly adapting receptors
(RARs)
– Slowly adapting stretch
receptors (SARs)
Chemical stimuli:
–C-fibers

4. Cough Reflex: Afferent Pathway
• Vagus nerve is major
afferent pathway
• Stimuli arise from:
– Ear
– Pharynx
– Larynx
– Lungs
– Tracheobronchial tree
– Heart
– Pericardium
– Esophagus

5. Efferent Pathway: 4 Phases
1. Inspiratory Phase
2. Compressive Phase
3. Expiratory Phase
4. Relaxation Phase

6. History
 Cough characteristics / associations :
Presence of post -nasal drip/catarrh/rhinitis
Worsened by posture / meals
Worse at night / in cold environments
Dry or productive
Associated wheeze / breathlessness
 Medications: ACE-I
 H/O Atopy
 Presence of other respiratory diseases
associated with cough
(COPD,asthma,bronchiectasis etc.)
 Age / Gender
 Smoking history
 Occupational history

7. Physical Examination
Should look for:
Clubbing
Crepitation
Lymphadenopathy
Signs of lung collapse
Signs of pleural effusion
Horner’s syndrome etc.

8. Investigations
CXR
Spirometry
Bronchial provocation test
Sputum test
Sinus imaging
HRCT of chest
Bronchoscopy
Endoscopy of upper GIT
24 hr esophageal pH monitoring etc

9. American College
of Physicians 2006
Cough Guidelines
• Evidence-based
• Should be used in
conjunction with “clinical
judgment”
• Divides cough in adults by
duration: acute, subacute,
chronic

10. Etiology of chronic cough in
adults

11. Differential Diagnosis
Top 4 in immunocompetent patient with normal
CXR:
– Upper airway cough syndrome
– Asthma
– Gastroesophageal reflux disease
– Non-asthmatic eosinophilic bronchitis
Chronic cough has two or more causes in 18
to 62 percent of patients, and three causes in
up to 42 percent of patients.

13. Upper Airway Cough Syndrome
(UACS)
• Also called “Post-nasal drip
syndrome” (PNDS)
• Mechanism: secretions from
nose/sinuses stimulate upper
airway cough receptors;
inflammation increases
receptor sensitivity
• Classic symptoms: “tickle” in
throat; throat clearing,
hoarseness, nasal congestion
• Cough may be the only
symptom in ~ 20%

14. Upper Airway Cough Syndrome
(UACS)
• Signs (may be absent): inflamed nasal
mucosa, secretions in posterior
oropharynx
• Consider underlying causes: allergies,
chronic sinusitis, overuse of alpha-agonist
nasal sprays
• Diagnostic/Therapeutic trial: 1st
generation anti-histamine/decongestant
combination medication for 2 weeks

15. Asthma
• Mechanism: inflammatory mediators, mucus,
bronchoconstriction stimulate cough receptors
• Classic symptoms: intermittent wheeze
• Cough may be the only symptom in 7-57%
patients - “Cough-variant asthma”
• Signs (often absent): expiratory wheezing on
chest exam

16. Asthma
• Diagnostic tests:
– Spirometry, before and after
bronchodilator: partially
reversible airflow obstruction
– Methacholine inhalation
challenge: positive
• Diagnostic/
Therapeutic trial:
inhaled corticosteroid +
bronchodilator for
≥ 8 weeks

17. Gastroesophageal Reflux Disease (GERD)
 Acid reflux can stimulate the afferent limb of
the cough reflex
 by irritating the upper respiratory tract
without aspiration or
 by irritating the lower respiratory tract through
aspiration
GERD can also cause chronic cough by stimulating an
esophageal-bronchial cough reflex.
 Daily heartburn and
regurgitation suggest a GERD-induced chronic cough.
These symptoms may be absent in “silent” GERD.

18. A Vicious Cycle
COUGH
REFLUX INCREASED
ABDOMINAL
PRESSURE

19. Gastroesophageal Reflux
Disease (GERD)
• Classic symptoms: heartburn,
sour taste in mouth
• Cough may be only symptom in
75% patients with chronic cough
• Diagnostic tests:
– 24-hour esophageal pH
monitoring

20. Gastroesophageal Reflux
Disease (GERD)
• Diagnostic/Therapeutic trial: gastric acid
suppression with proton pump inhibitor
(e.g. omeprazole) for 2 months,≥
combined with diet and lifestyle
modification

21. Non-Asthmatic Eosinophilic
Bronchitis (NAEB)
• Eosinophilic airway inflammation WITHOUT
variable airflow obstruction or airway
hyperresponsiveness.
• Diagnostic tests:
- Spirometry: normal
- Methacholine challenge:
normal
- Induced sputum: >3%
eosinophils
• Diagnostic/Therapeutic trial:
inhaled corticosteroid for 4≥
weeks

23. All that coughs is not UACS,
asthma, GERD, or NAEB!

25. ACE-inhibitor therapy
• Dry cough in 3-30% patients
• Begins 1 week to 6 months after drug
started
• Usually resolves 1-7 days after stopping
therapy, but can take 4 weeks
• An ARB may be substituted for the ACE-I

26. Continued on next slide…

27. Chronic Cough, continued:

28. Psychogenic/Habitual cough
Diagnosis of exclusion.
Do not cough during sleep.
Not awakened by cough.
Do not cough during enjoyable distractions.
Common triggers: changes in ambient
temperature; taking a deep breath; laughing;
talking on the telephone for more than a few
minutes; exposure to cigarette smoke, aerosol
sprays or perfumes etc.

29. Differentials with abnormal
CXR
Any patient with chronic cough identified
as having underlying structural
disease (on the basis of symptoms, signs
and / or CXR) should be managed
according to recommended treatment
guidelines or be referred to the
Respiratory Medicine Service for further
assessment if needed.