Approach to (Raf)

Question 1

How is chronic cough defined?

Answer 1

> 4-8 weeks of cough (Kendig’s)

Question 2

Approach to chronic cough

Answer 2

Dry cough:
o Allergic rhinitis and post nasal drip
o Asthma
o GERD
o Tracheobronchomalacia +/ - an associated abnormality like vascular ring
o Habit cough
o Interstitial lung disease – eg. Eosinophilic lung disease
o Post infectious cough: Pertussis and Mycoplasma pneumonia (Kendig’s)
o Drugs like ACEi
- Wet cough:
o Cystic fibrosis
o Primary ciliary dyskinesia
o Retained foreign body – consider in child<5 years, typically wet cough, but could be dry. Associated: wheeze, halitosis.
o Aspiration
o Immunodeficiency
o Chronic endobronchial suppurative disease:
§ Non-CF bronchiectasis- eg. Immunodeficiency
§ Persistent bacterial bronchitis

• Other:
• Chronic infection: TB (cough, monophasic wheeze from hilar lymphadenopathy or tuberculoma), fungal (histoplasmosis, cocciodoides), Chlamydia pneumonia, Mycoplasma pneumonia, non-tuberculous mycobacteria
• In a younger infant–>Chalmydia trachomatis, CMV can cause “afebrile pneumonia of infancy”
• Non-infective bronchitis: from exposure to environmental pollutants - environmental tobacco smoke, biologic pollutants (eg, dust mite, mold, pets), nitrogen dioxide from unvented gas heating, and particulate matter from wood stoves and cooking
• Mediastinal mass

Question 3

Differential diagnosis for bronchiectasis?

Answer 3

• idiopathic (most common)
• impaired host defences
  
  • cystic fibrosis (CF) (most common cause in children)
  • primary ciliary dyskinesia, e.g. Kartagener syndrome, Young syndrome
  • primary immunodeficiency disorder, e.g. common variable immunodeficiency, hypogammaglobulinaemia, chronic granulomatous disease
  • HIV/AIDS 15,16
• postinfective (most common known non-CF cause in adults)
  
  • bacterial pneumonia and bronchitis, e.g S. aureus, H. influenzae, B. pertussis
  • mycobacterial infection, e.g. tuberculosis, Mycobacterium avium-intracellulare complex
• allergic and autoimmune
  
  • allergic bronchopulmonary aspergillosis (ABPA)
  • connective tissue disease, e.g. rheumatoid arthritis 6, Sjögren syndrome, systemic lupus erythematosus (SLE) 7
  • inflammatory bowel disease
• obstruction
  
  • severe obstructive lung disease: asthma or chronic obstructive pulmonary disease (COPD)
  • neoplasm, e.g. bronchial carcinoid, bronchogenic carcinoma
  • inhaled foreign bodies
• congenital
  
  • bronchial tree malformations, e.g. Mounier-Kuhn syndrome, Williams-Campbell syndrome, pulmonary sequestration, bronchial atresia
  • alpha-1-antitrypsin deficiency
• others
  
  • chronic aspiration
  • traction bronchiectasis due to diffuse lung disease, e.g. pulmonary fibrosis
  • radiation-induced lung disease
  • post-transplantation

Question 4

CXR findings in bronchiectasis

Answer 4

• Tram track opacities in cylindrical bronchiectasis
• Air fluid levels in cystic bronchiectasis
• Ring shadows (from seeing bronchi end on)
• Increased bronchovascular markings

Question 5

CT findings for bronchiectasis

Answer 5

• bronchus visualised within 1 cm of pleural surface
  
  • especially true of lung adjacent to costal pleura
  • most helpful sign for early cylindrical change
• lack of tapering
• increased bronchoarterial ratio
• bronchial wall thickening: normally wall of bronchus should be less than half the width of the accompanying pulmonary artery branch
• mucoid impaction
• air-trapping and mosaic perfusion
  Signs described on CT include:
• tram-track sign
• signet ring sign

Question 6

For what bronchoarterial ratio do you consider a diagnosis of bronchiectasis?

Answer 6

> 1-1.5 in adults

Question 7

review differential diagnosis of bronchiectasis as based on location

Answer 7

See note on Bronchiectasis (Radiology)