Approach to a patient withChronic Cough

Presented by-Dr. Debasish Bhowmick

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.

Cough Reflex: Afferent Pathway

Mechanical stimuli:– Rapidly adapting receptors

(RARs)– Slowly adapting stretch

receptors (SARs)

Chemical stimuli:–C-fibers

Cough Reflex: Afferent Pathway• Vagus nerve is major

afferent pathway

• Stimuli arise from:– Ear– Pharynx– Larynx– Lungs– Tracheobronchial tree– Heart– Pericardium– Esophagus

Efferent Pathway: 4 Phases

1. Inspiratory Phase

2. Compressive Phase

3. Expiratory Phase

4. Relaxation Phase

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

Physical Examination

Should look for:

Clubbing

Crepitation

Lymphadenopathy

Signs of lung collapse

Signs of pleural effusion

Horner’s syndrome etc.

InvestigationsCXRSpirometryBronchial provocation testSputum testSinus imagingHRCT of chestBronchoscopyEndoscopy of upper GIT24 hr esophageal pH monitoring etc

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

Etiology of chronic cough in adults

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.

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%

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

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

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

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.

A Vicious Cycle

COUGH

REFLUX INCREASED ABDOMINAL PRESSURE

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

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

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

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

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

Continued on next slide…

Chronic Cough, continued:

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.

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.