Pleurisy is an inflammation of the membrane that surrounds and protects the lungs (the pleura). Inflammation occurs when an infection or damaging agent irritates the pleural surface. Sharp chest pains are the primary symptom of pleurisy.
Pleurisy, also called pleuritis, is a condition that generally stems from an existing respiratory infection, disease, or injury. In people who have otherwise good health, respiratory infections or pneumonia are the main causes of pleurisy. This condition used to be more common, but with the advent of antibiotics and modern disease therapies, pleurisy has become less prevalent.
The pleura is a double-layered structure made up of an inner membrane, which surrounds the lungs, and an outer membrane, which lines the chest cavity. The pleural membranes are very thin, close together, and have a fluid coating in the narrow space between them. This liquid acts as a lubricant, so that when the lungs inflate and deflate during breathing, the pleural surfaces can easily glide over one another.
Pleurisy occurs when the pleural surfaces rub against one another, due to irritation and inflammation. Infection within the pleural space is the most common irritant, although the abnormal presence of air, blood, or cells can also initiate pleurisy.
These disturbances all act to displace the normal pleural fluid, which forces the membranes to rub, rather than glide, against one another. This rubbing irritates nerve endings in the outer membrane and causes pain. Pleurisy also causes a chest noise that ranges from a faint squeak to a loud creak. This characteristic sound is called a "friction rub".
Pleurisy cases are classified either as having pleural effusion or as being “dry.” Pleural effusion is more common and refers to an accumulation of fluid within the pleural space; dry pleurisy is inflammation without fluid build-up.
Less pain occurs with pleural effusion because the fluid forces the membrane surfaces apart. However, pleural effusion causes additional complications because it places pressure on the lungs. This leads to respiratory distress and possible lung collapse.
Causes and symptoms
A variety of conditions can give rise to pleurisy. The following represent the most common sources of pleural inflammation:
- infections, including pneumonia, tuberculosis, and other bacterial or viral respiratory infections
- immune disorders, including systemic lupus erythematosus, rheumatoid arthritis, and sarcoidosis
- diseases, including cancer, pancreatitis, liver cirrhosis, and heart or kidney failure
- injury, from a rib fracture, collapsed lung, esophagus rupture, blood clot, or material such as asbestos
- drug reactions, from certain drugs used to treat tuberculosis (isoniazid), cancer (methotrexate, procarbazine), or the immune disorders mentioned above (hydralazine, procainamide, phenytoin, quinidine).
The hallmark symptom of pleurisy is sudden, intense chest pain that is usually located over the area of inflammation. Although the pain can be constant, it is usually most severe when the lungs move during breathing, coughing, sneezing, or even talking. The pain is usually described as shooting or stabbing, but in minor cases it resembles a mild cramp.
When pleurisy occurs in certain locations, such as near the diaphragm, the pain may be felt in other areas such as the neck, shoulder, or abdomen (referred pain). Another indication of pleurisy is that holding one’s breath or exerting pressure against the chest causes pain relief.
Pleurisy is also characterized by certain respiratory symptoms. In response to the pain, pleurisy patients commonly have a rapid, shallow breathing pattern. Pleural effusion can also cause shortness of breath, as excess fluid makes expanding the lungs difficult. If severe breathing difficulties persist, patients may experience a blue-colored complexion (cyanosis).
The distinctive pain of pleurisy is normally the first clue physicians use for diagnosis. Doctors usually feel the chest to find the site of inflammation. A stethoscope is used to listen for abnormal chest sounds (such as the friction rub) as the patient breathes. Sometimes, a friction rub is masked by the presence of pleural effusion and further examination is needed for an accurate diagnosis.
To diagnose the illness that is causing pleurisy, doctors must evaluate the patient’s history, additional symptoms, and laboratory test results. A chest x ray may also be taken to look for signs of accumulated fluid and other abnormalities. Computed tomography (CT) scan and ultrasound scans are more powerful diagnostic tools used to visualize the chest cavity.
The most helpful information in diagnosing the cause of pleurisy is a fluid analysis. Once the doctor knows the precise location of fluid accumulation, a sample is removed using a procedure called thoracentesis. In this technique, a fine needle is inserted into the chest to reach the pleural space and extract fluid.
Several laboratory tests are performed to analyze the chemical components of the fluid and determine whether bacteria or viruses are present. Pleurisy associated with rheumatoid arthritis produces a distinctive pattern of tissue cells in the pleural fluid.
Cancerous growths also shed cells into the tissue fluid. While most cases of pleurisy associated with cancer are secondary developments from a primary tumor, in some instances the pleurisy is the first indication of a malignancy.
In certain instances a biopsy of the pleura may be needed for microscopic analysis. A sample of pleural tissue can be obtained several ways: with a biopsy needle, by making a small incision in the chest wall, or by using a thoracoscope (a video-assisted instrument for viewing the pleural space and collecting samples).
Alternative treatments can be used in conjunction with conventional treatment to help heal pleurisy. Acupuncture and botanical medicines are alternative approaches for alleviating pleural pain and breathing problems.
Poultices (crushed herbs applied directly to the skin) of respiratory herbs can assist in the healing process. An herbal remedy commonly recommended is pleurisy root (Asclepias tuberosa), so named because of its use by early American settlers who learned of this medicinal plant from Native Americans.
Pleurisy root helps to ease pain, inflammation, and breathing difficulties brought on by pleurisy. This herb is often used in conjunction with mullein (Verbascum thapsus) or elecampane (Inula helenium), which serve as expectorants to clear excess mucus from the lungs.
Other respiratory herbs that are used in the treatment of pleurisy include boneset (Eupatorium perfoliatum), catnip (Nepata cataria), and feverfew (Chrysanthemum parthenium).
Herbs thought to combat infection, such as echinacea (Echinacea species), are also included in herbal pleurisy remedies. Antiviral herbs, such as Lomatium dissectum and Ligusticum porteri, can be used if the pleurisy is of viral origin.
Traditional Chinese treatments are chosen based upon the specific symptoms of the patient. The treatment principles are to harmonize the collaterals, regulate the qi, and possibly to treat stagnation of Phlegm and Blood. Acupuncture, ear acupuncture, and herbal remedies are used to treat chest pains.
The herb ephedra (Ephedra sinica) opens air passages and alleviates respiratory difficulties in pleurisy patients. One pill of Xue Fu Zhu Yu Wan (Blood Mansion Eliminating Stasis Pill) can be taken twice daily to treat stabbing chest pain. The basic herbal formula, to which additional herbs are added for specific symptoms, is:
- Chuan Lian Zi (Fructus meliae toosendan), 10 g
- Jiang Xiang (Ligum dalbergiae odoriferae), 3 g
- Jie Geng (Radix platycodi), 5 g
- Xiang Fu (Rhizoma cyperi), 10 g
- Xuan Fu Hua (Flos inulae), 6 g
- Yan Hu Suo (Rhizoma corydalis), 10 g
- Yu Jin (Tuber curcumae), 10 g
- Zhi Ke (Fructus aurantii) 5 g
Other alternative remedies for pleurisy include:
- Aromatherapy. Essential oils can be effective when used as massage oils or inhaled with steaming water. Rosemary relieves pain. Peppermint relieves pain and decreases inflammation. Eucalyptus eliminates infection.
- Diet. Dietary recommendations include eating fresh fruits and vegetables, and adequate protein. The patient should ingest omega–3 fatty acids’ which are fats with anti-inflammatory activity found in salmon, mackerel, herring, and flaxseed oil.
- Homeopathy. Homeopathic treatment, chosen by a trained practitioner based on the pattern of symptoms experienced by the patient, can be effective in resolving pleurisy.
- Hydrotherapy. Contrast hydrotherapy applied to the chest and back, along with compresses (cloths soaked in an herbal solution), can assist in the healing process.
- Supplements. Taking certain nutritional supplements, especially large doses of vitamin C, may also provide health benefits to persons with pleurisy.
The pain of pleurisy is usually treated with analgesic and anti-inflammatory drugs, such as acetaminophen, ibuprofen, and indomethacin. Sometimes, a painful cough will be controlled with codeine-based cough syrups. However, as the pain eases, a person with pleurisy should try to breathe deeply and cough to clear congestion, otherwise pneumonia may occur.
The treatment used to cure pleurisy is determined by the underlying cause. Pleurisy from a bacterial infection is treated with antibiotics. Specific therapies designed for more chronic illnesses can often cause pleurisy to subside. In some cases, excess fluid must be removed by thoracentesis or a chest tube. If left untreated, a more serious infection, called empyema, may develop.
Prompt diagnosis, followed by appropriate treatment, ensures a good recovery for most pleurisy patients. Generally speaking, the prognosis for pleurisy is linked to the seriousness of its cause.
Preventing pleurisy is often a matter of providing early medical attention to conditions that can cause pleural inflammation. Maintaining a healthy lifestyle and avoiding exposure to harmful substances (for example, asbestos) are more general preventative measures.