SM_171: Occupational Disorders Flashcards
What are the challenges of diagnosing occupational lung disease?
- Clinical and pathologic expressions indistinguishable from those of non-occupational disease
- Long latency period between onset of exposure and first expression of disease
- Clinical effects of many toxic exposures related to exposure dose
- Multifactorial causation
- Underreporting of work-related conditions
What are occupations at risk for silicosis?
- Agriculture
- Mining
- Road construction
- Glass
- Ceramics
- Foundries
- Construction
What are silica-related health effects?
- Silicosis: chronic simple silicosis, progressive massive fibrosis, accelerated silicosis, acute silicosis/silicoproteinosis
- Mycobacterial infections: TB and NTM
- Industrial bronchitis and COPD
- Extrapulmonary disease (autoimmune and renal)
- Lung cancer
- Pleural abnormalities
Describe chronic simple silicosis
- Usually recognized first by abnormal radiograph: upper lobe nodules
- Latency period 20-30 years
- Few symptoms and normal pulmonary function tests in early disease
- May slowly progress
Describe progressive massive fibrosis
- Mass > 1 cm in diameter
- Mixed pattern of restriction and obstruction on pulmonary function tests
- Cicatricial emphysema may be seen
- Usually symmetric, occasionally R>L
- Asymmetry, rapid greowth, and cavitation possible but should prompt search for mycobacterial disease or cancer
Describe acute silicosis / silicoproteinosis
- Requires intense high exposures - often associated with sandblasters
- Symptoms appear within weeks to 2 years of exposure
- Pathologic findings of alveolar proteinosis
How are silica exposure and COPD connected?
- Increased symptoms of chronic bronchitis in silica-exposed people with silicosis
- Silica potentiates effects of smoking in emphysema patients
- Accelerated rates of FEV1 decline reported in several industries using silica: miners, granite crushers, concrete, and pottery workers
How are silica exposure and lung cancer connected?
- Association w/ lung cancer, strongest in those w/ silicosis
- Causal link confounded by co-exposure to radon, arsenic, diesel exhaust, and cigarette smoke
- Association seen in miners, foundry, quarry, and diatomaceous earth workers
What are diseases caused by inhalation of coal mine dust and the body’s reaction to it?
- Fibrotic diseases - damage/destroy lung tissue: silicosis, coal workers pneumoconiosis
- Airflow diseases (COPD) - block movement of air in and out of lungs: bronchitis, emphysema, mineral dust airways disease
- Infectious diseases - dust reducses immunity: TB
What are the medicolegal and public health aspects of managing patients with pneumoconiosis?
- Removal from exposure
- Counseling / legal referral: workers compensation, benefits, exposure screening and education
- Impairment / disability assessment
- Medical follow-up and assessment of disease progression / complications
What are the pathologic features of hypersensitivity pneumonitis?
Hypersensitivity pneumonitis
- Loosely organized granuloma
- Area surrounding alveoli largely unaffected
Hypersensitivity pneumonitis is ______
Hypersensitivity pneumonitis is an immunologically-mediated inflammatory disease of the lung induced by inhalation of certain organ ducts
- Repeated inhalation, sensitization, and immunologically-mediated lung damage
- Acute form from intense exposure
- Chronic form from recurrent low-level exposure
What are the causes of hypersensitivity pneumonitis?
- Bacteria: farmer’s lung, mushroom worker’s lung, bagassosis, humidifier lung
- Fungi: malt worker’s lung, suberosis, cheese worker’s lung
- Amoebae: humidifier lung
- Animal proteins: bird breeder’s lung, wheat weevil lung
- Chemicals: isocyanate lung
- Mixed: metal working fluids
What is the definition of occupational lung disease?
The occupation
- Was the sole cause of the disease
- Was one of the factors which caused the disease
- Aggravated, accelerated, or exacerbated the condition
Making a diagnosis of occupational lung disease requires ______ and ______ and/or ______ and/or ______ and/or ______
Making a diagnosis of occupational lung disease requires history of exposure and chest imaging abnormalities and/or lung function abnormalities and/or laboratory testing (immunology) and/or lung pathology
Describe the components of an occupational history
- Where do you work? (chronology)
- What job titles have you had?
- What were your specific job duties?
- Specific exposures
- Description of workplace and work processes
- Use of person protective equipment
- Similar symptoms in co-workers
Chest radiography is useful in screening and surveillance of ______ exposed workers
Chest radiography is useful in screening and surveillance of dust exposed workers
- Has been helpful in exposure-response relationships
- Documents failures of dust control
Describe pathology samples for occupational disease
- Not often obtained in cases of living workers for medical legal reasons
- Necessary when there is confusion about the diagnosis
- Often obtained at autopsy, lung biopsy, or lung resection for other reasons
- Subject to sampling bias
Describe the role of the clinician in occupation lung disease medical and public health responses
- High index of suspicion
- Disease recognition (careful occupational and environmental history taking)
Accurate disease diagnosis and exposure removal - Benefits counseling and referral
- Diagnosis may be a sentinel health event (index case of a disease, disability, or untimely death) - public health intervention needed to protect others with shared exposure (prevention)
What is the role of medical surveillance in occupational lung disease?
- Primary prevention: control exposures
- Secondary prevention: identify early disease and prevent progression
- Tertiary prevention: treatment of established disease
_______ is a respiratory disease found in coal miners that has increased in prevalence
Pneumoconiosis (black lung) / pulmonary massive fibrosis is a respiratory disease found in coal miners that has resurged in prevalence
(pulmonary massive fibrosis is complicated pneumoconiosis)
