Interstitial Lung Disease

• Conditions included in interstitial lung disease

  • Idiopathic pulmonary fibrosis
  • Secondary pulmonary fibrosis
  • Hypersensitivity pneumonitis
  • Cryptogenic organising pneumonia
  • Asbestosis
• Presenting features of interstitial lung disease

  • Shortness of breath on exertion
  • Dry cough
  • Fatigue
• Typical findings in patients with idiopathic pulmonary fibrosis

  • Bibasal fine end-inspiratory crackles
  • Finger clubbing
• Patients with idiopathic pulmonary fibrosis are ideal for OSCEs as they are stable and have good signs
• Diagnosis of interstitial lung disease involves

  1. Clinical features

  2. High-resolution CT scan (HRCT) of the thorax (showing a typical “ground glass” appearance)

  3. Spirometry
• Spirometry results in interstitial lung disease

  • May be normal or show a restrictive pattern
  • FEV1 and FVC are equally reduced
  • FEV1:FVC ratio greater than 70%
• Other investigations for interstitial lung disease diagnosis

  1. Lung biopsy

  2. Bronchoalveolar lavage
• Idiopathic Pulmonary Fibrosis


  • Features progressive pulmonary fibrosis with no apparent cause
  • Presents with an insidious onset of shortness of breath and dry cough over more than 3 months
  • Affects adults over 50 years old
  • Prognosis is poor with a 2-5 years life expectancy from diagnosis
• Medications licensed to slow the progression of idiopathic pulmonary fibrosis

  • Pirfenidone (reduces fibrosis and inflammation)
  • Nintedanib (reduces fibrosis)
• It usually affects adults over 50 years old
• The prognosis is poor, with a 2-5 years life expectancy from diagnosis
• Medications that can slow the progression of the disease

  • Pirfenidone
  • Nintedanib
• Pirfenidone


  • Reduces fibrosis and inflammation through various mechanisms
• Nintedanib


  • Reduces fibrosis and inflammation by inhibiting tyrosine kinase
• Drugs that can cause pulmonary fibrosis

  • Amiodarone (also causes grey/blue skin)
  • Cyclophosphamide
  • Methotrexate
  • Nitrofurantoin
• Conditions that can lead to secondary pulmonary fibrosis

  • Alpha-1 antitrypsin deficiency
  • Rheumatoid arthritis
  • Systemic lupus erythematosus (SLE)
  • Systemic sclerosis
  • Sarcoidosis
  • Hypersensitivity Pneumonitis
• Hypersensitivity Pneumonitis


  • Involves type III and type IV hypersensitivity reaction to an environmental allergen
• Bronchoalveolar lavage


  Performed during a bronchoscopy procedure. The airways are washed with sterile saline to gather cells, after which the fluid is collected and analysed
• Bronchoalveolar lavage


  • Raised lymphocytes (lymphocytosis) are suggestive of hypersensitivity pneumonitis
• Management of Hypersensitivity Pneumonitis


  Involves removing the allergen, oxygen where necessary, and steroids
• Specific causes of lung reactions

  • Bird-fancier’s lung is a reaction to bird droppings
  • Farmer’s lung is a reaction to mouldy spores in hay
  • Mushroom worker’s lung is a reaction to specific mushroom antigens
  • Malt worker’s lung is a reaction to mould on barley
• Cryptogenic Organising Pneumonia


  • Involves a focal area of inflammation of the lung tissue. It can be idiopathic or triggered by various factors
• Diagnosis of Cryptogenic Organising Pneumonia

  Requires a lung biopsy as the definitive investigation. Diagnosis is often delayed due to similarities to infectious pneumonia
• Treatment of Cryptogenic Organising Pneumonia

  Is with systemic corticosteroids
• Asbestosis


  • Refers to lung fibrosis related to asbestos exposure. Asbestos causes lung fibrosis and is oncogenic
• Problems caused by asbestos inhalation

  • Lung fibrosis
  • Pleural thickening and pleural plaques
  • Adenocarcinoma
  • Mesothelioma
• Patients may be eligible for compensation if they develop asbestos-related health conditions. Deceased patients with occupational asbestos exposure must be referred to the coroner