Rheumatoid Lung

Question 1

Rheumatoid Lung Dance

Answer 1

Interstitial lung disease caused by rheumatoid arthritis
May also have concomittant bronchiectasis, pleural effusion

Rheumatoid arthritis
1. Symmetrical deforming arthropathy of small joints of hands
2. Steroid purpura, Cushingoid, proximal myopathy - corticosteroid treatment
3. Peripheral oedema - membranous glomerulonephritis from RA, gold, penicillamine

Interstitial lung disease
3. Finger clubbing
4. Reduced cricoid notch distance
5. Reduced but symmetrical chest expansion (hyperinflation in BOOP)
6. Dull percussion, reduced fremitus, reduced air entry **over bases*
7. Fine end-inspiratory crepitations at lung base, may extend up to midzone, not alter with coughing
(less commonly RA may cause apical fibrosis)
8. +/- inspiratory clicks, coarse crepitations alter with coughing - concomittant bronchiectasis
9. Look for pleural effusion - reduced sound, stony dullness, reduced fremitus
10. Look for pulmonary hypertension
11. Look out for sputum mug

Question 2

What are the respiratory manifestations of rheumatoid arthritis? (6+4)

Answer 2

1. Pleural thickening and effusion
2. Basal fibrosis - RA, gold, MTX
3. Apical fibrosis +/- fibrobullous - RA
4. Pneumonitis and pulmonary arteritis
5. Bronchiectasis
6. Bronchiolitis obliterans (RA, gold, penicillamine)
7. Pulmonary nodules
8. Caplan syndrome
9. Bronchial carcinoma

Question 3

What is the commonest respitatory manifestation of RA?
How common is ILD in RA? Can ILD precedes RA?

Answer 3

Commonest: Pleural disease +/- pleural effusion

ILD presents in 25% of patients, up to 50% having reduced diffusion capacity
Most patients have known RA prior to ILD. Some cases ILD may precede onset of arthritis by months or years

Question 4

Discuss about pulmonary nodules in RA

Answer 4

Histologically similar to subcutaneous nodules
Single or multiple nodules over pleural or parenchyma
Commonly over upper lobes
Varying size few mm to 6cm, increase or decrease to severity of systemic disease

Nodules do not compromise respiratory functions
But prone to secondary infections, cavitation, bronchopulmonary fistula

Question 5

How does pulmonary hypertension develop in patients with RA?

Answer 5

1. Lung parenchyma disease - ILD or bronchiectasis
2. Rarely pulmonary vasculature inflammation (primary pulmonary hypertension)

Question 6

What are the characteristics of RA pleural effusion?

Answer 6

Exudative
Never blood stained
High protein and LDH, LDH > 1000
Low glucose
Low complement C3 and C4
High rheumatoid factor (higher than serum)

Question 7

What is Caplan’s syndrome?

Answer 7

Pneumoconiosis (pulmonary massive fibrosis) in RA with single or multiple nodules
Made worse with smoking
Also seen in coal miners, silica exposure