Cough

» Paediatrics

Overview

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.

Defintion
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

Approach

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

COMMON CAUSES OF COUGH
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.

CAUSES OF CHRONIC COUGH
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
Bronchiectasis