Cough

Question 1

COUGH
Outline mechanism, pathway

Answer 1

• *Cough**
• Forced exhalation against closed glottis
• Protective mechanism to clear secretions/irritants
• Receptors - in upper airway mucosa, oesophagus & pericardium
• Sensory afferent glossopharyngel/vagus
• Efferent vagal- phrenic/spinal motor nerves
• Effector glottis, intercostal, diaphragm

Definition – chronic cough (Australian + US guidelines)
Acute = <2 weeks
Protracted acute = 2-4 weeks
Chronic = >4 weeks (British >8 weeks)

Cough nature (wet vs dry) most important predictor of a specific cause of cough in children
Dry implies minimal lower airway secretions
Kids <4 rarely expectorate

Question 2

COUGH
What are ddx for dry cough, outline features of psychogenic & habitual cough

Answer 2

• *Chronic-non specific cough of childhood**
• Dry cough, no cause found after reasonable evaluation (CXR/PFTs)
• No specific pointers on history/exam
• Should resolve gradually- re-evaluate if not improving
• Can be related to post-infective (paroxysmal, day&night, dry, worse with exercise)
• *Psychogenic cough (habit cough)**
• Teenage girls mainly
• Honking/hacking quality
• Persistent throughout day but settles during sleep
• Not associated with SOB/sputum
• Also boys 7-10yrs
• Throat clearing cough, may be related to tics
• Refer to specialist if >3mo duration or not improving with psychological support

Should respond to reassurance, psychological support & distraction therapies