T4 L13: Interstitial lung disease Flashcards
What 4 things make up the interstitium?
Alveolar epithelium, capillary endothelium, basement membrane, and connective tissue
What is the mechanism for lung fibrosis?
It’s unknown
What are the functions of the extracellular matrix of the lungs?
Elasticity, low resistance for effective gas exchange, and tissue repair
What is the extracellular matrix?
A 3D fibre filled with macromolecules like collagen and elastin
What are the 3 types of occupational lung disease?
Silicosis, coal miners lung, and asbestosis
What are common causes of hypersensitivity pneumonitis?
Mould and bird proteins
What is sarcoidosis?
A condition where inflamed cells clump together to make non-necrotising granulomas. Cause is unknown but it’s a disease of the young (30-60 years)
What are come clinical presentations of idiopathic pulmonary fibrosis?
Slowly progressive exertional dyspnoea, non-productive cough, dry inspiratory bibasal crackles, clubbing of fingers, abnormal pulmonary function tests
What is idiopathic fibrosis?
Unknown cause but it causes progressive, irreversible fibrosis that is fatal. Its limited to the lungs and has minimal inflammation. Usually a diseases of the elderly but affects men twice as often
What is the prognosis for someone with idiopathic fibrisis?
50% survive past 3 years, 20% survive past 5 years
How is idiopathic pulmonary fibrosis treated?
No cure but Pirfenidone and Nintedanib slow progression. These drugs are often poorly tolerated and patients develop weight loss, GI upset, and photosensitivity
What part of the lung does hypersensitivity pneumonitis affect and why?
The upper lobes because it’s inhaled
How does hypersensitivity pneumonitis develop?
When a antigen in inhaled
What are the clinical presentations of acute hypersensitivity pneumonitis?
SOB, cough, fever, crackles within 4-6 hours of exposure
What is hypersensitivity pneumonitis often misdiagnosed as?
Infection
What are the subacute clinical presentations of hypersensitivity pneumonitis?
Gradual onset, weight loss is common
What are the chronic clinical presentations of hypersensitivity pneumonitis?
Incomplete resolution when the antigen is removed, may lead to irreversible fibrosis
How is hypersensitivity pneumonitis diagnosed?
Using serum precipitins (circulating igG antibody-antigen complexes)
How is hypersensitivity pneumonitis managed?
Avoidance of the antigen or using steroids
Which 3 drugs are known to be associated with drug-induced interstitial lung disease?
Nitrofurantoin (for UTI), Amiodarone (an anti-arrhythmic), and Methotrexate (an immunosuppressant)
How is connective tissue disease-related interstitial lung disease managed?
Treat the underlying disease with biologics, steroids, or immunosuppressants
Which diseases cause connective tissue disease-related interstitial lung disease?
Rheumatoid arthritis, scleroderma, sjogrens, and polymyositis
What are some common clinical presentations of sarcoidosis?
Cough, SOB, wheeze, erythema nodosum, lupus pernio, nodules, anterior uveitis, bells palsy, mononeuropathies
What is Lofgrens Syndrome?
A condition characterised by Erythema nodosum, bilateral hilar lymphadenopathy, and Arthralgia. It has an excellent prognosis and is usually self-limiting
