Interstitial lung diseases Flashcards
What are ILDs?
Term to describe a number of conditions that primarily affect lung parenchyma in a diffuse manner
General clinical features of ILDs
dyspnea on exertion, non-productive paroxysmal cough, abnormal breath sounds + CRX, restrictive pulmonary spirometry
General pathology of ILDs
fibrosis + remodelling of interstitial, chronic inflammation, hyperplasia of type II pneumocytes
How can ILDs be broadly classified?
- those with known cause e.g. occupational, hypersensitivity reactions (extrinsic allergic alveolitis)
- those associated with systemic disorders e.g. sarcoidosis, RA, SLE
- idiopathic
What are the following a cause of? Bird-fanciers and pigeon-fanciers lung Farmer's and mushroom workers lung malt worker;s bagassosis or sugar workers?
extrinsic allergic alveolitis
In extrinsic allergic alveoli’s, what does inhalation of allergens provoke in sensitive individuals?
a type 3 hypersensitivity reaction
Acute presentation of extrinsic allergic alveolitis
fevers, riggers, myalgia, dry cough, dyspnea, crackles
Chronic presentation of extrinsic allergic alveolitis
increasing dyspnea, weight loss, type 1 resp failure
cor pulmonae
What would CXR for extrinsic allergic alveolitis show?
Acute: upper-zone mottling/consolidation
Chronic: upper zone fibrosis, honeycomb lung
What would blood tests for extrinsic allergic alveolitis show?
ESR up
Positive serum precipitins
What would lung function tests show for extrinsic allergic alveolitis?
Reversible restrictive defect
Acute Mx for extrinsic allergic alveolitis
Remove allergen
Give O2
Oral prednisolone
Chronic Mx for extrinsic allergic alveolitis
avoid exposure
long term steroids
compensation?
What’s sarcoidosis?
multisystem granulomatous disorder of unknown cause
Presentation of acute sarcoidosis
erythema nodosum (red skin lumps) polyarthralgia (aches in the joints)
Pulm Sx: dry cough, progressive dyspnea, decreased exercise tolerance + chest pain
What would blood test show for sarcoidosis?
Raised ESR, lymphopenia, raised LFT, serum ACE raised,
What does tissue biopsy show in sarcoidosis?
non-caseating granulatomata
what is punched out lesions in terminal phalanges a feature of?
sarcoidosis
What do 90% of those with sarcoidosis have on their CRX?
abnormal CXR with bilateral hilar lymphadenopathy (BHL) +/- pulm infiltrates or fibrosis
Mx sarcoidosis
Bed rest + NSAIDs for acute
Corticosteroids if more serious (parenchymal lung disease, uveitis, hypercalcaemia, neuro or cardiac involvement)
What is idiopathic pulmonary fibrosis (IPF) also known as?
crytogenic fibrosing alveolitis
whats the most common cause of interstitial lung disease?
idiopathic pulmonary fibrosis
in IPF, what does progressive fibrosis lead to?
it limits pt’s ability to breath –> terminal chest infection + hypoxic damage
Presentation of IPF
dry cough, exertion dyspnea, malaise, weight loss, arthralgia
signs: cyanosis, finger clubbing, fine end-inspiratory crepitations
Blood results for IPF
ABG (PaO2 down, PaCO2 raised if severe)
CRP raised
immunoglobulins raised
What is usual interstitial pneumonia?
The histological variable pattern of inflammation + fibrosis you see in IPF
Mx for IPF
best supportive care
DO NOT use high dose steroids
? clinical trials for lung transplant
Secondary causes of ILD
RA Asbestos exposure (may --> malignant mesothelioma and lung cancer)
Both seem to show the pattern of usual interstitial pneumonia
