Dr Robin Smith Dept of Respiratory Medicine. Interstitial and Occupational Lung Disease. Interstitial Disease. Any disease process affecting lung interstitium (ie alveoli, terminal bronchi). Interferes with gas transfer
- exposure to agent (e.g. drug, dust etc)
common - lungs, lymph nodes, joints, liver, skin, eyes
less common - kidneys, brain, nerves, heart
erythema nodosum, bilateral hilar lymphadenopathy, arthritis, uveitis, parotitis, fever.
Differential diagnosis = TB (tuberculin test -ve), Lymphoma, Carcinoma, fungal infection.
- Angiotensin Converting Enzyme (ACE) levels as activity marker (NOT diagnostic test).
- raised calcium
- increased inflammitory markers
Steroids if vital organ affected (eg impaired lung function, heart, eyes, brain, kidneys)
Immunosuppression (eg azathioprine, methotrexate)
monitor chest X-ray and pulmonary function for several years
and lung infiltrares -Sarcoidosis
Signs: +/- pyrexia, crackles (no wheeze!), hypoxia
CxR: widespread pulmonary infiltrates
Treatment: oxygen, steroid and antigen avoidance
CHRONIC: repeated low dose antigen exposure over time progressive breathlessness and cough
(also known as Cryptogenic Fibrosing Alveolitis)
Most common interstitial lung disease
OE: clubbing, bilateral fine inspiratory crackles,
Ix: restrictive defect (reduced FEV1 and FVC with normal or raised FEV1/FVC ratio, reduced lung volumes, low gas transfer CxR - bilateral infiltrates;
CT scan - reticulonodular fibrotic change, worse at the lung bases. The presence of “ground-glass” suggests reversible alveolitis; fibrosis is irreversible.
Secondary (eg rheumatoid, SLE, systemic sclerosis, drugs - amiodarone, busulphan, bleomycin, penicillamine, nitrofurantoin, methotrexate).
oral steroids ± immunosuppressive drugs (eg azathioprine combined with N-acetyly cisteine) worth trying if patient is <75 years and evidence of acute inflammation on CT scan - some response in 30%.
NB treatment is aimed as slowing future progression rather than reversing established fibrosis.
Oxygen if hypoxic.
Lung transplantation in young patients
Future treatments: ?Anti-fibrotic agents
pulmonary artery vasodilators
1- Benign pleural plaques - asymptomatic
2- Acute asbestos pleuritis - fever, pain, bloody pleural effusion
3- Pleural Effusion and Diffuse pleural thickening - restrictive impairment
4- Malignant Mesothelioma - incurable pleural cancer. Presents with chest pain and pleural effusion. No available treatment - fatal within two years.
and Bronchial Ca
due to mesothelioma
Useful clinical & X-ray teaching sites