- Clinical science
Asbestosis is a type of pneumoconiosis caused by the inhalation of asbestos fibers and occurs primarily as a result of occupational exposure. After a long latency period, this condition manifests with nonspecific symptoms, e.g., coughing and dyspnea, which are caused by fibrotic changes in the lungs. The diagnosis is established based on a history of occupational exposure (such as working with textiles, cement, ship-building, insulation) and characteristic changes on chest x-ray (reticular opacities and pleural plaques). Currently, there is no curative treatment for asbestosis. Management consists of measures that provide symptomatic relief like oxygen therapy, prompt antimicrobial treatment of respiratory infections, cessation of exposure, and immunization against influenza and pneumococcal pneumonia. Long-term exposure to asbestos can lead to complications like fibrosis, respiratory failure, and malignancy (especially bronchogenic carcinoma, and mesothelioma). Pleural effusion may be the first sign of a malignant mesothelioma. A combination of chemotherapy, surgery, and/or radiation therapy is used to manage malignant mesothelioma. However, the prognosis of patients with malignant mesothelioma is poor, with the mean survival time being ∼ 1 year.
- Type of caused by inhalation of asbestos fibers
- Occupations involving the manufacture or demolition of ships, plumbing, roofing, insulation, heat-resistant clothing, and brake lining
- Inhalation of airborne asbestos fibers into alveoli → inflammation and fibrosis of pleural parenchyma → risk of carcinogenic effects
A high cumulative dose of asbestos is associated with a higher incidence of asbestosis. In smokers, the disease progresses more rapidly because mucociliary clearance is impaired.
Chest x-ray (classification according to the International Labor Office): diffuse bilateral infiltrates predominantly in the lower lobes
- Interstitial fibrosis
- Supradiaphragmatic and pleural reticulonodular opacities/plaques
- In some cases,
- Parenchymal fibrosis (especially basilar, peribronchiolar, and septal)
- Pleural plaques and subpleural linear opacities
- Chest x-ray (classification according to the International Labor Office): diffuse bilateral infiltrates predominantly in the lower lobes
- Pulmonary function test
- Bronchoalveolar lavage ;: microscopic asbestos bodies
- Microscopic asbestos bodies
- Definition: primarily malignant tumor that develops from mesothelial cells
- Sex: ♂ > ♀ (3:1)
- Age range: ∼ 40–70 years
- Etiology: : secondary to asbestos exposure
- Histological classification: epithelial mesothelioma, sarcomatoid mesothelioma, biphasic mesothelioma (a mix of epithelial and sarcomatoid mesothelioma)
- Clinical findings
- Pleurocentesis; : bloody (exudative) pleural effusion
- Imaging (chest x-ray and CT) ;:
Laparoscopy, thoracoscopy, and pleuroscopy with stained biopsy ;: mesothelioma cells and psammoma bodies
- Risk of implantation metastasis is ∼20% .
- It is important to differentiate mesothelioma from adenocarcinoma.
- Treatment: radiation, with or without chemotherapy (cisplatin and pemetrexed); surgery (pleurectomy or pneumonectomy) may be indicated in cases with severely impaired pulmonary function
- Prognosis: poor, with a mean survival time of ∼ 1 year
- Progressive respiratory failure
- Caplan syndrome
We list the most important complications. The selection is not exhaustive.
- The use of asbestos in the US is restricted.
- Any new uses of asbestos have been banned, as have corrugated paper, rollboard, commercial or specialty paper, and felt flooring containing asbestos.