Pleural plaques are the most common manifestation of past asbestos exposure. Depending on how hard they are looked for, a majority of workers exposed to asbestos in the past will be found to have them.
The area of lung involved is the outer layer of pleura called the parietal pleura. Pleural plaques can be small or large, sparse or multiple but usually bilateral.
Plaques start as a hyaline area of thickening on the pleura. As years go by they become more obvious. This is because they calcify after about 20 years since first exposure. It is this calcification that often brings them to attention on scanning.
Plaques are an indicator of previous asbestos exposure. They do not go on to cause other conditions; it is the past exposure to asbestos that does that. Plaques are benign. Plaques on their own do not generally cause any reduction in lung function unless the plaques are very extensive. On rare occasions pleural plaques can cause chest pain. However, chest pain as a result of pleural plaques can be very severe and treatment may eventually involve the use of narcotic analgesics.
People, even those who have only had brief exposure, can develop pleural plaques. Whilst as stated previously, they are generally seen as a marker of past asbestos exposure, they can in some instances cause chest pain and if extensive can restrict breathing capacity.
As with many asbestos diseases there is no effective treatment. Of course chest pain can arise from various causes and the diagnosis of pleural plaque pain is a diagnosis of exclusion. Other causes of the pain usually need to be excluded before pleural plaques can be identified as the cause of pain. In addition pleural plaques can be very extensive and interfere or restrict the function of the lung causing breathlessness on exertion.
It is important to remember that pleural plaques are generally a marker of past asbestos exposure and usually do not cause symptoms and do not develop into a more serious asbestos disease. Pleural plaques are evidence of past asbestos exposure and it is the asbestos exposure itself that can cause more severe disease. Pleural plaques do not become malignant and asbestos related pleural disease is a benign, non-cancerous condition.