Pleurisy, or pleuritis, in an inflammation of the pleurae (thin, moist membranes that cover the lungs and line the chest cavity).
The pleurae normally reduce the friction between the chest structures as the lungs expand and contract. Inflammation of the plurae causes breathing to become painful and less effective.
The membranous pleura that encases each lung is composed of two close-fitting layers; between them is a lubricating fluid. If the fluid content remains unchanged by the disease, the pleurisy is said to be dry. If the fluid increases abnormally, it is a wet pleurisy, or pleurisy with effusion. If the excess fluid of wet pleurisy becomes infected, with formation of pus, the condition is known as purulent pleurisy or empyema.
There are two types of pleurisy: dry and wet pleurisy. In dry pleurisy, the more common condition, the inflamed pleurae rub directly against each other. In wet pleurisy, fluid oozes from the inflamed tissue into the space between the lungs and the chest wall. This fluid may compress the lungs, making breathing difficult.
Both types of pleurisy often occur as complications of respiratory tract infections, such as pneumonia, viral infections, and tuberculosis, and are more likely to develop in persons who are highly susceptible to such infections. They also can be caused by a tumor or an injury.
Some cases are due to certain gastrointestinal tract diseases, particularly of the liver and pancreas, which can inflame the diaphragm (the large muscle separating the chest and abdominal cavities) and the portions of the pleurae that cover the diaphragm.
Pleurisy may be caused by infection, injury, or tumor. Pleurisy may be a complication of underlying lung diseases, particularly of pneumonia, or sometimes of tuberculosis, lung abscesses, or influenza. Pleurisy can also occur spontaneously without any preceding problem.
The major symptom of dry pleurisy is a sharp, stabbing pain towards the side and lower part of the chest. The pain may also be felt along the shoulders, neck and abdomen. Any movement involving the chest, such as breathing or coughing, will aggravate the pain, which may be accompanied by shortness of breath, a dry cough, and fever.
Wet pleurisy is characterized by similar symptoms, but there may also be difficulty in breathing.
A diagnosis of pleurisy usually begins with a physical examination, during which the doctor listens to the chest with a stethoscope for the low-pitched grating sound that occurs with each breath in a case of dry pleurisy. If fluid in the lungs is suspected, the physician may percuss, or tap on, the chest wall to determine the level and amount. The skin near the affected area is often found to be tender.
If wet pleurisy is suspected, a sample of the fluid oozing from the pleurae will usually be obtained (by inserting a needle directly in the pleura) and analyzed. A tuberculin test may be done to learn whether tuberculosis is a factor. An x-ray study is very helpful in detecting the presence of pleural fluid.
To treat pleurisy, the doctor will first need to treat the underlying infection or disease, often with antibiotics.
The symptoms of pleurisy can be relieved somewhat by resting. Strapping the chest firmly with an adhesive elastic bandage is sometimes recommended; however, it may prevent deep breathing and coughing up of mucus, both of which are necessary to clear the respiratory tract.
Painkillers may help to relieve chest discomfort at least enough so that the patient will not need to stifle the painful coughing that is necessary to loosen the mucus.
Anti-inflammatory medications and even cortisone drugs are very effective in relieving the inflammation and pain, particularly in dry pleurisy.