Interstitial lung diseases:
Groups of diseases due to thickening of alveolar walls with inflammatory cells and exudate
Can be from:
acute respiratory distress syndrome (ARDS)
granulomas (eg sarcoidosis)
fibrosis (eg fibrosing alveloitis)
exposure to organic dusts (eg Farmer lung)
exposure to non-organic dusts (eg asbestosis, silicosis)
Multisystem granulomatous disease.
See Rheumatology chapter
Fibrosing Alveolitis (CFA):
Unknown aetiology. Up to a third are associated with connective tissue diseases.
Characterised by increase in inflammatory cells in alveoli and interstitium and some pulmonary fibrosis.
Clinical features – exertional dyspnoea, dry cough, malaise, weight loss, joint symptoms, nail clubbing, cyanosis
Treatment – immunosuppression
Extrinsic allergic alveolitis:
Inhaled antigen hypersensitivity reaction in lungs in those that are sensitised.
Clinical features – 4-8 hrs after exposure fever, malaise, dry cough, dyspnoea; chronic increasing malaise, weight loss, exertional dyspnoea, crepitations
Treatment – avoid exposure to allergens; steroids