Coal worker's pneumoconiosis

Overview

•Caused by prolonged inhalation of coal dust (typically >10-20 years of mining) → upper zone fibrosis
•Progressive exertional dyspnoea - insidious onset over years
•Dry cough - chronic, non-productive in simple CWP
•Simple CWP may be asymptomatic - found incidentally on CXR
•PMF (progressive massive fibrosis) - nodules coalesce into large masses (>1 cm); causes significant breathlessness and cor pulmonale
⚠️
CWP does NOT cause pleural plaques - these point to asbestosis. CWP does NOT cause eggshell hilar calcification - this points to silicosis.

Investigations

•CXR - bilateral upper zone small nodular opacities (simple CWP); large conglomerate upper zone opacities in PMF
•Spirometry - restrictive pattern: reduced FVC, normal or elevated FEV1:FVC ratio, no reversibility with bronchodilator

🏆 Gold standard

•HRCT chest - confirms upper zone nodular opacities, extent of fibrosis, distinguishes simple CWP from PMF
🧠
Upper lobe fibrosis mnemonic - CHARTS: Coal worker's pneumoconiosis, Histiocytosis X, Ankylosing spondylitis/Allergic bronchopulmonary aspergillosis, Radiation, Tuberculosis, Silicosis/Sarcoidosis. All other common causes (asbestosis, IPF, amiodarone, connective tissue diseases) cause LOWER zone fibrosis.

Management

•No disease-modifying treatment - antifibrotics (pirfenidone, nintedanib) have no established role

🥇 First-line

•removal from further coal dust exposure - most important intervention to prevent progression to PMF
•Smoking cessation - accelerates decline and increases lung cancer risk
•Pulmonary rehabilitation
•LTOT - if resting PaO2 <7.3 kPa on two occasions or <8 kPa with complications (cor pulmonale, polycythaemia)
•Industrial Injuries Disablement Benefit (IIDB) - CWP is a prescribed occupational disease in the UK; advise patients to claim via DWP

Complications

•PMF - progressive even after exposure has ceased
•Cor pulmonale - right heart failure from pulmonary hypertension; peripheral oedema, raised JVP
•Increased TB susceptibility - coal dust impairs macrophage function
•Caplan syndrome - rheumatoid pulmonary nodules superimposed on CWP in patients with rheumatoid arthritis

CWP vs silicosis - key differentiators

CWP vs silicosis
FeatureCWPSilicosis
OccupationCoal minersMiners, pottery/stone workers
CXR zoneUpper zone fibrosisUpper zone fibrosis
Eggshell hilar calcificationAbsentPresent (classic)
SpirometryRestrictiveRestrictive