Occupational lung disorders Flashcards
Examples (of pneumoconiosis)
Coal workers pneumoconiosis Bauxite fibrosis Berylliosis Asbestosis Siderosis Silicosis (Potters rot)
Cause/pathology of coal workers pneumoconiosis
Inhaling coal dust
Dust particles accumulate in the lung parenchyma and are engulfed by macrophages
These macrophages then die, releasing enzymes resulting in tissue fibrosis
Cause of bauxite fibrosis (Shavers disease)
Inhaling bauxite fumes
Cause/pathology of berylliosis
Caused by inhaling beryllium
Causes granuloma formation (of giant cells, macrophages and epithelioid cells)
Progressive dyspnoea with pulmonary fibrosis
What is granuloma made up of
(Giant cells)
Macrophages
Epithelioid cells
Examples of other granulomatous conditions other than berylliosis
Tuberculosis
Leprosy
Cat-scratch disease
Sarcoidosis
Cause/pathology of asbestosis
Inhalation of asbestos fibres
Associated with malignant mesothelioma
CXR also shows pleural plaques
What cell contains fusiform rods
Macrophages
Types of asbestosis (which has higher fibrogenicity)
White asbestos - lowest fibrogenicity
Blue asbestos - highest
Define fibrogenicity
promoting the development of fibers
Cause/pathology of siderosis
Caused by inhaling iron particles
Benign with no apparent respiratory symptoms or altered lung function
Cause of silicosis
Caused by inhaling silica particles that can not by removed by respiratory defences
Pathology of silicosis
Macrophages engulf the silica particles releasing tumour necrosis factor (TNF) and cytokines that induce fibroblasts, resulting in fibrosis and collagen deposition.
Eggshell calcification of hilar lymph nodes is apparent on CXR + nodular lesions in the upper lobes
Which pneumoconiosis increases risk of TB infection
Silicosis
What is pneumoconiosis
The accumulation of dust in the lungs and the reaction of the tissue to its presence
Describe Progressive Massive Fibrosis
Due to progression of coal workers pneumonconiosis
Patients develop round fibrotic masses mostly situated in upper lobes
Atypical destruction of lung, resulting in emphysema and airway damage
DYSPNOEA and Fibrosis
Sputum may be black
Describe serum sample of progressive massive fibrosis or asbestosis or silicosis
Rheumatoid factor and anti-nuclear antibodies are both often present in the serum of patients
Complications of Progressive Massive Fibrosis
Disease can progress or develop even after coal exposure has ceased and may lead to respiratory failure
Describe lung function test of Progressive Massive Fibrosis
Mixed restrictive and obstructive ventilatory defect with loss of lung volume, irreversible airflow limitation and reduced gas transfer
Silicosis:
Describe Spirometry and CXR
CXR appearance show diffuse nodular pattern in upper and mid-zone and thin streaks of calcification (egg-shell calcification) of the hilar nodes
Spirometry shows a restrictive ventilatory defect
Presentation of silicosis
Progressive dyspnoea
Increased incidence of TB
Management of silicosis
Avoiding exposure to silica and claim compensation
*Different types of asbestos
Which are most fibrogenic
90% of asbestos is chrysolite (white asbestos) which is the least fibrogenic
6% is crocidolite (blue asbestos) which is the most fibrogenic and most likely to cause asbestosis and mesothelioma due to the fact that it is readily trapped in the lung
4% is amosite (brown asbestos) which is the least common and has intermediate fibrogencicity
Complications of asbestos
Risk of primary lung cancers (usually adenocarcinomas)
Significant time lag however between exposure and development of disease
What is asbestosis + pathophysiology
Type of interstitial lung disease
Deposition in lung distal to the terminal bronchiole
Fibrosis of the lungs caused by asbestos dust (may or may not be associated with fibrosis of the parietal or visceral layers of the pleura)
Progressive
Also causes pleural plaques and increases risk of mesothelioma and bronchial adenocarcinoma
Clinical presentation of asbestosis
Progressive disease characterised by breathlessness and progressive dyspnoea and accompanied by finger clubbing and bilateral basal end-inspiratory crackles
Management of asbestosis
Symptomatic e.g. corticosteroids
What is Byssinosis
Cotton dust (instead of asbestos)
Chest tightness, cough and breathlessness soon after exposure
Bad in those already with asthma
Most common type of pneumoconiosis
Simple pneumoconiosis
Chest X-ray of pneumoconiosis
Fine micro nodular shadowing
CXR used to grade it
What can also cause symptoms of pneumoconiosis
COPD related to smoking
