Interstitial Lung Disease
Sir, this patient has interstitial lung disease affecting both lower lobes (upper lobes) as
evidenced by fine velcro-like late inspiratory crepitations heard best
posteriorly(anteriorly) in the lower one third bilaterally. This is associated with
clubbing(50%) and a non-productive cough.
Chest excursion was reduced bilaterally with a normal percussion note and vocal
resonance. Trachea is central and apex beat is not displaced.
There are no signs of pulmonary hypertension or cor pulmonale. There are also no
features of polycythemia.
Patient respiratory rate is 14 breaths per minute and there are no signs of respiratory
distress. There are also no signs of respiratory failure. There is also no nicotine
staining of the fingers and I note that the patient is cachexic looking with wasting of
the temporalis muscles.
In terms of aetiology, there is no symmetrical deforming polyarthropathy of the hands
to suggest RA, or cutaneous signs to suggest presence of SLE, dermatomyositis or
scleroderma as these conditions may be complicated by pulmonary fibrosis.
With regards to treatment, patient is not Cushingoid and does not have papery thin
skin or steroid purpura to suggest chronic steroid usage. On inspection there are no
surgical scars to suggest open lung biopsy.
I would like to complete the examination by asking for a detailed drug history as well
as an occupational history.
In summary, this patient has got pulmonary fibrosis affecting bilateral lower lobes.
There are no complications of pulmonary hypertension, cor pulmonale and
polycythemia. He is clinically not in respiratory failure and has no features of chronic
steroid usage. The differential diagnoses include collagen vascular disease, drugs,
occupational causes and idiopathic pulmonary fibrosis.
What are the differential diagnoses for clubbing and crepitations?
Mitotic lung conditions
What are the characteristic auscultatory findings?
Late, fine inspiratory crepitations
Disappears or quietens with the patient leaning forwards
What are the causes of fibrosis?
S – Silicosis, sarcoidosis
C- coal worker pnemoconiosis
A- Ankylosing spondylitis, ABPA
R – radiation
T – TB
I – Idiopathic pulmonary fibrosis
O- others ie drugs
Cytotoxics – MTX, Aza, bleomycin, bulsulphan, cyclo, chlorambucil
CNS - Amitryptyline, phenytoin and carbamazepine
CVS - Amiodarone, hydralazine, procainamide
Antibiotics - Nitrofurantoin, isoniazid
Antirheumatics – Gold, sulphasalazine
N – Neurofibromatosis, Tuberous sclerosis
E – Extrinsic allergic alveolitis (acute symptoms within 6 hrs of inhaled
allergens eg farmer’s lungs)
P – pulmonary haemorrhage syndromes
A – alveolar proteinosis
Secondary – Inhaled organic dusts(Silica, Al), chronic infection,
How would you classify interstitial lung disease? (ATS/ERS 2001)
Diffuse parenchymal lung disease(DPLD) of known cause
Collagen Vascular disease
RA, SLE, Dermatomyositis, Systemic sclerosis
Asbestosis, silicosis, extrinsic allergic alveolitis
Cytotoxic, CNS, CVS, Antibiotics and antirheumatic
Other idiopathic interstitial pneumonias
Cryptogenic organising pneumonia
Others - LAMs, histiocytosis
How would you diagnose idiopathic pulmonary fibrosis?
o Exclusion of other causes of ILD
o >50 yrs, insidious onset of dyspnea, > 3months, non-productive cough
o Typical physical findings
Radiological (see below)
Pathological (see below)
How would you investigate?
The diagnostic Ix of choice is a HRCT of the thorax but simple IX such as CXR and
LFT are useful:
bilateral basal reticulonodular shadows, peripheries, which advances
honeycombing in advanced cases (gps of closely set ring shadows)
loss of lung volume
Extent and distribution
Restrictive pattern (reduced TLC or VC with increased FEV1/FVC ratio)
Severity of restriction based on TLC
Reduced transfer factor (impaired gas exchange)
Dx – patchy reticular abnormalities, focal ground glass, architectural
distortion, volume loss, subpleural cyst, honeycombing (no consolidation or
Extent and severity – basal, peripheral, subpleural
NB: Similar to that of collagen vascular disease and asbestosis
Bronchoscopy – lavage
Predominantly lymphocyte responds to steroids and better Px= not UIP
Predominantly neutrophils and eosinophils means poor Px= UIP (if >20%
of eosinophils to consider eosinophilic lung disease)
IPF – Usual interstitial pneumonia
To rule out causes
How would you manage?
Education and counselling
Regular follow up and vaccinations
Treat underlying cause
Trial of steroids
If responding continue steroids
If not responding, cyclophosphamide or azathioprine
Eg penicillamine which has not been proven to be useful
Lung transplant (single lung transplantation)
Cor pulmonale - diuresis for heart failure
Polycythemia - venesection if Hct >55%
Respiratory failure – Oxygen therapy
Monitor for lung cancer
What are the good prognosticating factors?
Ground glass appearance on the CXR
Minimal fibrosis on lung biopsy
What is the clinical course of patients with IPF?
Median survival from time of dx about 3 years
What are the causes of death?
What is Hamman-Rich syndrome?
Rapidly progressive and fatal variant of interstitial lung disease