Interstitial Lung Disease Flashcards
Causes of interstitial lung disease.
Usual interstitial pneumonia (UIP)
Non-specific interstitial pneumonia (NSIP)
Extrinsic allergic alveolitis/Hypersensitivity Pneumonitis
Sarcoidosis
etc…
What is the most common cause of pulmonary fibrosis?
UIP
What is the most common cause of idiopathic interstitial pneumonias?
Idiopathic pulmonary fibrosis
What is the difference between usual interstitial pneumonia and idiopathic pulmonary fibrosis?
Usual interstitial pneumonia is the pathological pattern seen in e.g. idiopathic pulmonary fibrosis.
Idiopathic pulmonary fibrosis is the clinical diagnosis.
However not all UIP should be diagnosed as IPF.
UIP can also be seen in other diffuse parenchymal lung diseases such as pulmonary autoimmune rheumatic disease.
However to simplify things, in these flashcards IPF and UIP might be used interchangeably.
Clinical features of IPF.
Age > 50
Male > female
Progressive dyspnoea >3 mo
Progressive dry cough >3 mo
Respiratory failure
Hx of smoking
Examinatory findings in IPF.
Resp failure
Clubbing
Cyanosis
Fine inspiratory crackles bi-basally.
Raynaud’s
Cor pulmonale
When is clubbing seen in IPF.
In advanced disease
25-50% of cases
Not seen in drug induced ILD.
If there is new onset of finger clubbing, what should be considered?
Lung cancer
Investigations done in IPF.
Diagnosis is based on clinical features and HRCT
Who needs lung biopsy in IPF?
Most don’t as HRCT is usually confirmatory.
Young patients
Atypical clinical examination
Atypical radiological features
To rule out malignancy if there is suspicion of it.
Diagnostic approach of IPF.
HRCT
Final diagnosis is a combination of radiological, clinical and serological findings.
If still uncertain an MDT meeting will confirm whether a lung biopsy should be performed.
Explain the pathogenesis of IPF.
Repeated cycles of epithelial activation by some unidentified agent.
Dysregulated repair process
Inflammatory pathways leading to fibrosis
Abnormal epithelium reapir leading to abnormal fibroblastic foci.
Drugs that can cause IPF.
Amiodarone
Methotrexate
Bleomycin
Radiation
Nitrofurantoin
Cyclophosphamide
Diseases associated with IPF.
HS pneumonitis
RA
SLE
Scleroderma
Radiation therapy
Alpha-1 antitripsin deficiency
Findings on biopsy in IPF.
Cobblestone surface of the lung
Fibroblastic foci
Heterogeneity on histology.
CXR findings in IPF.
Small volume lungs
Reticulonodular shadowing
HRCT findings in IPF.
Basal distribution
Ground glass appearance
Honeycomb appearance in advanced disease
Reticulonodular shadowing
Traction bronchiectasis
Image shows a fibrotic lung (r) and a transplanted healthy lung (L)
When might a bronchoalveolar lavage be done to investigate ILD?
If there is an infective or malignant cause suspected.