Interstitial Lung Disease Flashcards
What is sarcoidosis?
A multisystem inflammatory disease of unkown etiology that predominantly affects the lungs and intrathoracic lymph nodes
- Granulomas don’t have a necrotic middle (unlike TB)
Systemic symptoms occur in 45% of sarcoidosis cases. What are they?
Fever Anorexia Fatigue Night sweats Weight loss
What are the non-systemic symptoms that can arise in 50% of sarcoidosis cases?
Pulmonary Dyspnoea on exertion Cough Chest pain Haemoptysis (rare)
How is sarcoidosis identified?
Most cases have symptoms (systemic or not)
5% of cases are asymptomatic and are found incidentally on X-Ray
What body systems can sarcoidosis manifest in?
Dermatological Ocular Cardiac Neurological Pulmonary
What are the lung signs that indicate sarcoidosis?
Dyspnoea
Cough
Vague chest discomfort
Wheezing
What are the four stages of sarcoidosis (unrelated to severity or changes in pulmonary function)?
Stage 1 - bilateral hilar lymphadenopathy without infiltration
Stage 2 - bilateral hilar lymphadenopathy with infiltration
Stage 3 - infiltration alone
Stage 4 - fibrotic bands, bullae, hilar retraction, bronchiectasis and diaphragmatic tenting
How is sarcoidosis diagnosed?
Once one of the above stages are identified on radiograph, they are biopsied for confirmation
Describe the granulomas found in sarcoidosis.
Non-necrotising
Inflammation
Asteroid bodies inside giant cells (not specific)
Name some causes of pulmonary fibrosis.
Berylliosis Radiation Extrinsic Allergic Alveolitis Allergic Bronchopulmonary Aspergillosis Sarcoidosis Tuburculosis
What is the most common cause of interstitial lung disease?
Idiopathic pulmonary fibrosis - IPF
What is pulmonary fibrosis?
Continuous fibrotic process of the lungs
- loss of lung tissue
- cyst formation
- scarring of the lungs
- accumulation of excess fibrous connective tissue
What is the aetiology and pathology of idiopathic pulmonay fibrosis?
Most common in men over the age of 50 Progressive breathlessness Bibasilar crackles Clubbing Peripheral interstitial pattern Subpleural honeycombing
What are the symptoms of IPF?
Breathlessness (worse with exercise) Hacking dry cough Fatigue and weakness (due to the inflammatory processes) Appetitie Weight loss Clubbing
How can IPF be diagnosed?
High resolution CT scan
VATS - biopsy
What is the pathophysiology of fibrosis?
Trigger causes repetitive alveolar epithelial injury
This alters the alveolar microenvironment
- oxidative stress
- profibrotic cytokines
- chemokines
- eicosanoid imbalance
- impaired fibrinolysis
- TIMPs-MMPs imbalance
The cumulative effect of these cause dysregulated repair, loss of epithelial cells and accumulation of mesechymal cells
Fibrosis
What is EAA?
Immunologically mediated inflammatory reaction in the alveoli and in the respiratory bronchioles
- T-cell mediated response (not atopy)
Often caused by heavy, repeated exposure to a trigger
Name some examples of EAA?
Farmer's lung Saw mill worker's lung Bird fancier's lung Mushroom worker's lung Malt worker's lung Suberosis
What are the symptoms of EAA?
Flu-like illness Cough High fever Chills Dyspnoea Chest tightness Malaise Myalgia
What are the symptoms of chronic exposure EAA?
Dyspnoea in strain Sputum production Fatigue Anorexia Weight loss
When does the EAA occur after exposure to the allergen?
4-8 hours after exposure
What are the radiological pulmonary signs of Henoch-Schonlein purpura?
Numerous poorly defined small (less than 5mm) opacities throughout both lungs
Sometimes with sparing of the apices and abses
Airspace disease: usually seen as ground glass opacities
Fine reticulation may also occur
Zonal distribution
Should be equally distrusted in both lungs
What is the pathology of Henoch-Schonlein purpura?
Bronchiolocentric pattern NNGI Foamy macrophages in alveolar spaces Chronic interstitial inflammation Organising pneumonia
