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What is involved? (including coding of cases) SABRE Case Studies and Information
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Coal Dust- a cause of interstitial pulmonary fibrosisA
67 year old man was referred to a respiratory physician after a chest X
ray performed pre-operatively was reported as abnormal. He had good
exercise tolerance, noticing no breathlessness on exertion, but did notice a
morning cough with yellowish sputum. He had smoked for 23 years, approximately
50 a day, but had given up 20 years before. He had worked as a coal miner over a
period of approximately 7 years between 1954-1955 and 1974-81, and had also been
employed transporting coal between a coal mine and the coal loader. He had no
other occupational dust exposure and kept no pets. Examination
revealed a fitman without clubbing or peripheral cyanosis. Bilateral late
end-inspiratory crackles were audible in the lung bases. Lung function revealed
a restrictive deficit with reduced lung volumes, a total lung capacity of 69%
predicted and a DLCO of 52% predicted. ESR and autoantibodies including
rheumatoid factor were normal. A high resolution CT scan of the chest showed
bilateral lower lobe interstitial fibrosis with some irregular honeycomb change. Clinical findings and results of investigations were compatible with interstitial pulmonary fibrosis rather than coal workers’ pneumoconiosis. Radiology in coal workers’ pneumoconiosis shows small, rounded opacities throughout the lung fields which are primarily mid and upper zonal in distribution. If the disease progresses, areas of progressive massive fibrosis may develop in the upper zones, with large rounded or sausage-shaped masses which may (rarely) cavitate. Usually, now crackles are audible. In contrast, interstitial pulmonary fibrosis (IPF) begins in the lower zones, with reticulo-nodular shadowing accompanied by late inspiratory crackles at the lung bases. IPF has however been reported in association with coal dust exposure although it is difficult to be certain in an individual case that this would not have occurred in the absence of dust. Some epidemiological studies have implicated metal dust, wood dust and other dusts as a causative factor for IPF and it seems likely that dust inhalation may play a larger part in its aetiology than has previously been realised. |