Armando Hasudungan
Biology and Medicine videos


Young children develop 6-12 respiratory tract infections per year, usually accompanied by cough. In most children, the cough is self-limiting (1-3 weeks), but it is sometimes prolonged. Cough that lasts for more then 3 weeks should be investigated.

Coughing is a protective reflex, a component of normal respiratory function, it enables irritants and foreign bodies to be expelled from the vulnerable respiratory tract, however it can also be voluntarily generated and therefore has non-reflex elements to assist/enhance with mucocilliary clearance

Acute cough: present up to 14 days/2 weeks
Prolonged acute cough: lasting 2 – 3 weeks
Chronic cough: present > 3 weeks
Cough Physiology

Physiology of Cough

Watch Video: Physiology of Cough

The anatomical structures of the respiratory tract are very sensitive structures

  • Larynx and Carina – especially sensitive (gateway to trachea and L + R main bronchus)
  • Trachea and Bronchi – very sensitive to light touch, a small amount of irritation can initiate the reflex
  • Terminal bronchioles and Alveoli – chemically sensitive to corrosive chemicals such as sulphur dioxide and chlorine gas


  • History
  • Examination
  • +/-Investigations
Alarm symptoms
Prominent dyspnoea, esp. at night or rest
Recurrent episodes of chronic wet or productive cough
Systemic Sx: fever, anorexia, wt. loss, failure to thrive
Feeding difficulties inc. choking or vomiting
Recurrent pneumonia
Additional breath sounds
Abnormal clinical respiratory examination
 Abnormal CXR


Conditions History Examination Workup Aetiology
Asthma Expiratory wheeze Oxygen, Fluids, bronchodilators +/-inhaled corticosteroids (depends on severity) Infection
Foreign body Sudden onset, history of choking Cough, Stridor CT, bronchoscopy Foriegn Body
Viral bronchiolitis Coryzal symptoms (2-3 days) followed by respiratory distress Fine inspiratory crackles, expiratory wheeze, fever Usually non required RSV
Acute URTIs Coryzal symptoms
Allergic rhinitis
Croup (laryngotracheobronchitis) Barking cough, coryza Low-grade fever, nasal flaring, respiratory retractions, stridor Generally not indicated Generally not indicated
Remember Young children develop 6-12 respiratory tract infections per year, usually accompanied by cough. In most children the cough is self-limiting (1-3) weeks
Condition History Examination Workup Aetiology
Smoking Exposure Smoking exposure Not significant Generally not indicated Smoking
GOR/GER Heartburn present, or if cough is worse at night or after eating specific foods
Sinusitis Nasal discharge, obstruction, toothache, unilateral facial pain, headache, fever “Sinusitis is not associated with cough” Tender sinuses, fever, inflamed nasal mucosa, pus exudating from middle meatus, maxillary transillumination
Post-nasal drip
Remember The most common causes of chronic cough in children are asthma, respiratory tract infections, and gastroesophageal reflux disease.


Flow chart of the management of wheeze in children

Management of persistent cough

Well child, normal examination

  • Watch and see
  • Avoid exposure to irritants such as cigarette smoke
  • Arrange follow up with paediatrician in 2-3 weeks.

Unwell child or abnormal examination 

  • These children will need further investigation and treatment and senior advice should be sought

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