Restrictive (Interstitial) Diseases Flashcards
What causes outwith the lungs can cause an interstitial disease?
Skeletal, muscular or compression due to abdominal obesity or ascites
What muscles would have to be affected to cause interstitial lung disease?
Intercostals or diaphragm
What conditions can cause muscle damage leading to ILD?
Myasthenia gravis and Guillain Barre syndrome and motor neurone disease
What happens to physiological volumes as ILD causes chronic alveolar under-ventilation?
Decreased PaO2, increased PaCO2, decreased lung volumes
What can the timing of ILDs be?
Acute, episodic or chronic
What can internal causes of chronic IDL be generally?
Environmental or occupational agents, drugs, systemic disease, idiopathic
What is ILD do to disease of?
Alveolar structures
What are 3 of the biggest groups of causes of ILD?
Fluid in alveolar spaces, inflammatory tissues in alveolar spaces and inflammation in alveolar walls (alveolitis)
What can fluid in alveolar air spaces cause?
Pulmonary oedema or non-cardiac pulmonary oedema
What causes pulmonary oedema?
Increased pulmonary venous pressure
What causes non-cardiac pulmonary oedema?
Normal pulmonary venous pressure but leaky capillaries due to sepsis or trauma
What can inflammatory components in alveolar spaces cause? Give examples.
Consolidation (infective pneumonia), infarction (PE, vasculitis)
What can cause alveolitis?
Granulomatous, extrinsic allergic (i.e. from birds), sarcoidosis, drugs, fibrosing, autoimmune
What is sarcoidosis?
Multi system disorder causing lymphadenopathy
What are other causes of ILD?
Rheumatoid arthritis, drugs, idiopathic
What is an example of something causing eosinophilic alveolitis?
Aspergillus
What do clinical features of ILD include?
Cough but no wheeze, breathless on exertion, finger clubbing, inspiratory crackles, central cyanosis
What can later stage ILD cause?
Pulmonary fibrosis
What can help make a diagnosis of ILD?
History, decreased lung volumes but normal peak flow, low SpO2, CXR, ECHO, HRCT
What will a CXR of ILD show?
Bilateral diffuse alveolar infiltrates
Why is an ECHO done for ILD?
To exclude heart failure
What is the treatment for ILD?
Remove trigger and treat inflammation: 1st line systemic corticosteroids 2nd line azathioprine. Give oxygen if hypoxic.
What is the last resort treatment for ILD?
Lung transplant
What is another name for extrinsic allergic alveolitis?
Hypersensitivity pneumonitis
What are examples of extrinsic allergic alveolitis?
Bird fancier’s lung, farmer’s lung
How would you describe a chronic case of extrinsic allergic alveolitis?
Extensive fibrosis with honeycombing and air-trapping
What are examples of pneumoconiosis?
Asbestosis, silicosis, coal worker’s lung
What type of lung disease is asbestosis?
Fibrotic
What colours can asbestos be and which is the worst?
Blue, brown, white- blue is worst
What is mesothelioma and when can it occur?
Malignant thickening of the pleura which can occur 20-40 years after asbestos exposure
Asbestos exposure combined with what makes a diagnosis even worse?
Smoking
What are some effects of traffic fumes?
Reduced lung growth in children and increased rates of asthma and COPD
What effects can many inhaled substances also have outside the lung?
Low birth weight, appendicitis, stroke, neurological outcomes
What is sarcoidosis?
Multi-system granulomatous type IV hypersensitivity of unknown cause
What type of granulomas are involved in sarcoidosis?
Non-caseating
Who is sarcoidosis less common in?
Smokers
What will acute sarcoidosis cause?
Erythema nodosum, bilateral hilar lymphadenopathy, arthritis and fever
What does chronic sarcoidosis cause?
Lung and skin infiltrates, peripheral lymphadenopathy and hypercalcaemia
What are some differentials of sarcoidosis?
TB, lymphoma, carcinoma, fungal infection
How is sarcoidosis diagnosed?
CXR, tissue biopsy, pulmonary function tests, bloods
What will a CXR of sarcoidosis cause?
Peripheral nodular infiltrate
What will a tissue biopsy of sarcoidosis show?
Non-caseating granulomas
What will pulmonary function tests for sarcoidosis show?
Restrictive pattern
What will blood tests for sarcoidosis show?
Increased calcium and inflammatory markers
What is the treatment for acute sarcoidosis?
Self limiting
What is the treatment for chronic sarcoidosis?
Oral steroids or immunosuppression if a major organ is involved
What is extrinsic allergic alveolitis/hypersensitivity pneumonitis?
Type III reaction to antigen lymphocyte alveolitis
How will acute extrinsic allergic alveolitis present?
A few hours after antigen exposure with dry cough, SOB, myalgia and fever
What signs may be present in acute extrinsic allergic alveolitis?
Crackles but no wheeze, hypoxia
How do you treat acute extrinsic allergic alveolitis?
Oxygen, steroids and antigen avoidance
What does chronic extrinsic allergic alveolitis cause?
Dry cough, progressive breathlessness, crackles
Where is the fibrosis most common in extrinsic allergic alveolitis?
Upper zones
What may be increased in extrinsic allergic alveolitis?
IgG
How do you treat chronic extrinsic allergic alveolitis?
Allergen avoidance and maybe oral steroids
Though no direct cause is known, what are some secondary causes of idiopathic pulmonary fibrosis?
Smoking, rheumatoid, SLE, sclerosis, drugs, asbestos
How does idiopathic pulmonary fibrosis present?
Progressive breathlessness and dry cough, clubbing and bibasal fine inspiratory crackles with decreased lung volumes
What will a CT of idiopathic pulmonary fibrosis show?
Reticulonodular shadowing worse at lung bases an peripheries
What is the buzzword associated with idiopathic pulmonary fibrosis?
Ground glass appearance on CXR
What are some differentials of idiopathic pulmonary fibrosis?
Occupational or connective tissue disease, LVF, extrinsic allergic alveolitis or sarcoidosis
What is the treatment for idiopathic pulmonary fibrosis?
No treatment really- don’t give steroids or immunosuppressants. Can give oxygen if hypoxic or lung transplant if patient is young
What is the prognosis for idiopathic pulmonary fibrosis?
Most progress to respiratory failure and live for 4/5 years after diagnosis
What are normal findings of coal worker’s pneumoconiosis?
CXR abnormality with no impairment of lung function
What will complicated pneumoconiosis show?
Massive fibrosis
What is Caplan’s syndrome and what will it show?
Rheumatoid pneumoconiosis- pulmonary nodules
What will show ‘egg shell calcification of hilar nodes’ on CXR?
Silicosis
What are the symptoms of benign pleural plaques?
Asymptomatic
What are symptoms of acute asbestos pleuritic?
Fever, pain and bloody pleural effusion
What will mesothelioma present with and what is the treatment?
Chest pain and pleural effusion- no treatment
What are type 1 alveolar cells?
Squamous epithelial cells which line most of the alveolar surface
What are type 2 alveolar cells?
Squamous epithelial cells which make up the rest of the alveolar surface but are also secretory cells
What exemplifies early stage acute ILD?
Adult respiratory distress syndrome
What is fibrosis get alveolitis?
Subpleural and basal fibrosis with variable inflammatory components
Are connective tissue diseases milder or harsher than fibrosis alveolitis?
Milder
What can often accompany connective tissue diseases?
Pleural effusions and rheumatoid nodules
What 4 things can asbestos cause?
Pleural plaques, interstitial fibrosis (asbestosis), bronchial carcinoma, mesothelioma
