Asbestos Related Pleural Disease (ARPD)
Asbestos related pleural disease (“ARPD”) is a generic term which covers a number of conditions. Pleural Plaques are technically a form of ARPD.
ARPD is a benign (non-cancerous) condition which in many cases causes respiratory impairment in the form of shortness of breath on exertion. The other types of ARPD are discussed below.
Benign Pleural Effusion
A benign pleural effusion is a build up of fluid in the space between the lung and the chest wall as a consequence of inflammation caused by asbestos fibre.
A benign pleural effusion causes symptoms in most cases. Symptoms include shortness of breath on exertion (due to the fluid compressing the lung and restricting its ability to expand and contract), chest discomfort and in some cases, fever. In some cases where only a small amount of fluid is produced, the benign pleural effusion can be symptomless.
In some cases, the body’s defence mechanisms work so that the fluid drains away naturally and no treatment is required. In other cases, symptoms persist and the fluid has to be drained away by a doctor. If the fluid re-accumulates, a procedure called a talc pleurodesis is performed in which talc is applied to the pleura to fuse it to the chest wall. This prevents the re-accumulation of the fluid.
Diffuse Pleural Thickening
Diffuse pleural thickening is the most common form of ARPD that causes permanent respiratory impairment. Diffuse pleural thickening is the result of a benign pleural effusion.
A benign pleural effusion results in the pleura of the lung thickening and adhering to the chest wall. The result is that the lung is “anchored” to the chest wall at the site of the pleural thickening.
Diffuse pleural thickening covers a much larger area than a Pleural Plaque. Diffuse pleural thickening is usually 5mm thick or more over one quarter of the chest wall.
In most cases, ARPD caused by a benign pleural effusion does not progress. Studies show that about one in five cases progress. That is usually because a further benign pleural effusion occurs after the initial effusion.