Interstitial Lung Disease Flashcards
List 3 types of interstitial lung disease.
Sarcoidosis
Idiopathic pulmonary fibrosis
Extrinsic allergic alveolitis (EAA)
Define sarcoidosis.
A multi-system inflammatory condition of unknown origin, mainly affecting the lungs and thoracic lymph nodes
Define idiopathic pulmonary fibrosis.
Chronic inflammation of the alveoli walls, leading to fibrosis and scarring
Define extrinsic allergic alveolitis (EAA).
An immunologically T-cell mediated inflammatory reaction in the alveoli and in the respiratory bronchioles
What is sarcoidosis caused by? (1)
Unknown
Describe the clinical features of sarcoidosis. (3)
Asymptomatic (5%)
Systemic symptoms (45%)
System specific symptoms (50%)
Describe the systemic symptoms of sarcoidosis. (5)
Fever Anorexia Fatigue Night sweats Weight loss
Describe the pulmonary symptoms of sarcoidosis. (3)
Dyspnoea Cough Discomfort Chest pain Wheeze Haemoptysis (rare)
Apart from pulmonary symptoms, what are the other system-specific symptoms which might be seen in sarcoidosis? (4)
Dermatological manifestations
Ocular manifestations (e.g. uveitis)
Cardiac manifestations (e.g. left heart dysfunction)
Neurological manifestations
How would you diagnose sarcoidosis? (4)
Diagnosis of exclusion
Respiratory examination
Lung/lymph node biopsy
Chest x-ray
Describe the histological features of sarcoidosis found on biopsy. (2)
Non-necrotising granuloma formation
Asteroid bodies in giant cells
Describe the classification of sarcoidosis on x-ray.
HINT: there are 4 classes.
CLASS 1: hilar lymphadenopathy
CLASS 2: hilar lymphadenopathy WITH infiltration
CLASS 3: infiltration only
CLASS 4: bullae, fibrotic bands, bronchiectasis, or diaphragmatic tenting
What are 2 other names for idiopathic pulmonary fibrosis?
Usual interstitial pneumonia (UIP)
Cryptogenic fibrosing alveolitis (CFA)
What is idiopathic pulmonary fibrosis caused by? (2)
Unknown
Non-specific interstitial pneumonia
List 5 KNOWN causes of pulmonary fibrosis (i.e. not IPF).
Give examples of each.
Occupational/environmental, e.g.
- Silicosis
- Abestosis
- EAA
Drug-induced, e.g.
- Amiodarone
- Nitrofurantoin
- Methotrexate
- Cocaine
Connective tissue disease, e.g.
- SLE
- RA
- Scleroderma
Primary lung diseases, e.g.
- Sarcoidosis
- Lymphangioleiomyomatosis (LAM)
Other causes, e.g.
- Genetics
- Tumours
- Irradiation
Describe the pathophysiology of idiopathic pulmonary fibrosis. (4)
- Emphysema causes loss of alveolar tissue
- Repetitive alveolar injury causes chronic inflammation and tissue remodelling
- This leads to a change in alveolar environment, e.g.
- Oxidative stress
- Pro-fibrotic cytokines
- Impaired fibrinolysis
- TIMP-MMP imbalance
- Eicosanoid imbalance - This leads to dysregulated repaid and loss of epithelial cells
a. This causes fibrosis and scarring
Which investigations would you do for idiopathic pulmonary fibrosis? (3)
High resolution CT
Video assisted thoracoscopic surgery (VATS)
Lung biopsy
What are the histological features of idiopathic pulmonary fibrosis seen on biopsy? (5)
Areas of normal and abnormal tissue Loss of alveolar space Fibroblastic foci Non-necrotising granuloma formation Bronchialisation
How do you treat idiopathic pulmonary fibrosis? (1)
FGF inhibitors
Describe the clinical features of idiopathic pulmonary fibrosis.
What are the symptoms? (5)
What are the signs O/E? (4)
SYMPTOMS: SOB Loss of apetite Weight loss Fatigue Hacking, dry cough
SIGNS ON EXAMINATION: Bibasilar crackles Finger clubbing Peripheral interstitial disease pattern Subpleural honeycomb appearance
List 3 causes of EAA.
Bird fancier’s lung: bird droppings
Farmer’s lung: mouldy hay
Mushroom worker’s lung: spores, moulds
Describe the clinical features of acute EAA. (7)
Flu-like illness Cough High fever Dyspnoea Chest tightness Malaise Mylagia
Describe the clinical features of chronic EAA.. (5)
Dyspnoea Sputum production Fatigue Anorexia Weight loss
Describe the signs of EAA on a CXR. (4)
Numerous poorly defined, small (<5mm) opacities throughout lungs
“Ground glass deformities”
Fine reticulation
Zonal distribution
