The first diagnosis of Asbestosis was made in the UK in 1924.
A diagnosis of Asbestosis will exclusively apply to pulmonary interstitial fibrosis which is asbestos induced. The term Asbestosis is often misused to describe other asbestos diseases.
Asbestosis will usually be diagnosed based on the following findings:
- An exposure to asbestos that is considered moderate to heavy;
- Clinical signs of interstitial fibrosis;
- X Ray finding opaque masses in the lung fields;
- Impairment of the lung function.
Diagnosing a person can take a significant period of time as the treating doctor will want to rule out all possible lung conditions such as lung scarring, rheumatoid arthritis:
It will begin with a doctor, usually your GP, taking your medical history and carrying out a physical examination. The doctor will ask about any medical conditions/problems you currently are suffering with, or have done in the past. The doctor will also discuss your occupational history with you, and more specifically, if you have ever worked with asbestos and your levels of exposure;
Depending on the outcome of the physical examination and the findings from the medical history, your GP may request one or more of the following tests:
- X-Ray of the Chest and/or Abdomen
- Computerised Tomography (CT)Scan
- Lung Function Tests
When an X Ray is performed Asbestosis will appear as shadowing in the lower parts of the lungs however if a person is suffering with a minor level of Asbestosis then it will be likely that a CT Scan will be required too, as it is more sensitive because it takes cross sectional images of the lungs. If a CT Scan is required to pick up signs of Asbestosis because it is an early case of the illness then they will usually considered as having little if any disability.
Lung function tests will be used to assess the disability of person and measure how effective your lungs work. They are used to find the reason behind breathing problems such as shortness of breath which is a common symptom for someone suffering with Asbestosis. It will measure:
- how much air you can take into your lungs and when compared with people of the same ages, height, sex etc the doctor can assess if you are within the normal range.
- how much air you can blow out of your lungs and how fast you can do it.
- how well your lungs deliver oxygen to your blood.
- the strength of your breathing muscles
Once the above investigations have been carried out then the doctor, usually the treating respiratory consultant, may decide that it is necessary to carry out a biopsy to confirm the diagnosis. A biopsy is when a sample of cells or tissue is removed to be examined under a microscope. To determine if a person has Asbestosis, a biopsy will be used to detect if there are any asbestos fibre and/or cancer in the lungs. There are several ways in which a biopsy can be performed and the one that is used will depend where the sample needs to be taken from:
- Thoraccentesis – a long needle is used to remove fluid for examination from the chest;
- Bronchoscopy – a thin, lighted tube called a bronchoscope is inserted either through the nose or mouth and then down into the lung to make it possible to examine the lung/s and air passages. If this procedure is used then the doctor may also take a sample of the cells with another tool.
- Fine-needle aspiration – a thin hollow needle is used to remove tissue or fluid from the lung. It may be necessary for the doctor taking the biopsy to be guided by a CT Scan.Thoracoscopy – a small incision is made in the chest and back. A thin, lighted tube called a thorascope is then placed into the chest between two ribs and the doctor can then have a clear view inside the chest to take the tissue sample. Anaesthesia is used when this is performed.
- Peritoneoscopy – a small incision is made in the abdomen and the doctor then inserts an instrument called a peritoneoscope.More extensive surgery will be necessary if a larger sample is required. It is not always necessary for a biopsy to be used in giving a diagnosis of Asbestosis however if a patient is thought to be at a higher risk of developing mesothelioma or lung cancer it is usually performed.
- More extensive surgery will be necessary if a larger sample is required.
The finding of asbestos bodies alone in the lungs is insufficient to lead to a diagnosis of Asbestosis as this only indicates an exposure to asbestos however it will assist in differentiating between the various Pneumoconiosis.
A diagnosis of Asbestosis is likely to follow excessive exposure to asbestos – a diagnosis of Asbestosis requires exposure of a minimum dose of 25 fibre mil years. To quantify fibres on the lungs there are several different methods which can be used: a light microscopy; scanning electronic microscopy or a transmission electron microscopy.
In most Asbestosis diagnosis, Pleural Plaques will also be visible from the radiography.
It is not uncommon for Asbestosis to begin in the respiratory system and advance down into the lungs however fibrosis limited only to the walls of the bronchioles does not indicate Asbestosis.
When a diagnosis of Asbestosis is being given it needs to be distinguished between other types of Pneumoconiosis such as:
- Anthracosis (miners lung) from exposure to coal dust;
- Silicosis exposure to silica and sometimes known as Potters rot or Grinders disease;
- Siderosis, from exposure to iron;
- Silicosiderosis exposure to both iron and silica.
It is possible however to have a diagnosis of more than one of the above Pneumoconiosis. A diagnosis of Asbestosis should also not be confused with lung diseases which are caused as a result of cigarette smoking such as:
- Emphysema – Obstructive lung disease which destroys the lung tissue round the bronchioles (smaller airways) causing them to lose their shape when we exhale and therefore making them inefficient in transferring oxygen into the blood and taking carbon dioxide out;
- COPD – chronic obstructive pulmonary disease;
- Respiratory bronchiolitis-associated interstitial lung disease.
A more difficult distinction which needs to be made when diagnosing Asbestosis is between a diagnosis of Idiopathic Pulmonary Fibrosis and one of Asbestosis, (also known as Pulmonary Fibrosis of Asbestosis). Idiopathic Pulmonary Fibrosis is very similar to Asbestosis however the two main differences between these two conditions are that Asbestosis will have inflammation which will be more advanced that in a diagnosis of Idiopathic Pulmonary Fibrosis and it will also have mild fibrosis of the pleura. The usual pattern of Idiopathic Pulmonary Fibrosis is called Usual Interstitial Pneumonia. Honeycomb changes in the lung are also common however in an advanced case of Asbestosis they can also be found.
The presence of asbestos bodies in the lung will generally assist in making a diagnosis of Asbestosis over another lung condition.