Pleurisy (also referred to as pleuritis) is the inflammation of the pleural layers surrounding the lungs. Pain is caused when there is friction between the layers. Pleurisy is a symptom of an underlying condition, not a condition in itself.
There are two layers of epithelium, the visceral pleura encases the lungs, and the parietal pleura covers the mediastrinum and chest wall. The two pleuras meet at the hilum. The pleural space between the pleuras contains lubricating fluid which helps prevent friction occurring between the two layers. The visceral pleura has an autonomic nerve supply which gives no pain sensation, whereas the parietal pleura has sensory nerve endings supplied by the phrenic nerve and therefore can experience pain.
Accumulation of pleural fluid suggests and increase of fluid production that exceeds the ability of the lymphatic system to remove it, or an obstruction in the pleural space.
Pleurisy is often caused by viral infections, but when a patient presents with pleurisy it is important first to rule out any life-threatening conditions such as MI and PE first. Although pleurisy is generally a symptom of an underlying condition, sometimes pleurisy is idiopathic.
Patients present with pain, particularly on breathing, as the pleura surfaces become inflamed and cause friction, this pleural rub can sometimes be heard as a scratching sound on inspiration. A key feature of pleurisy is that the pain is sharp and is exacerbated on coughing, sneezing or taking a deep breath.
Other symptoms of pleurisy include fever, chills, rigors, shallow breathing, shortness of breath, productive cough, diminished breath sounds.
By determining how acute the pleurisy is the underlying cause is easier to discover; acute (minutes-hours), sub-acute (hours-days) chronic (days to weeks) or recurrent. Chest x-rays are normal diagnostic tests; not only will they show a pneumothorax but also will detect if there is pleural effusion. D-dimer tests are normal practice to rule out PE, ECG to detect MI and also a sputum sample should be sent for analysis.
A full history should be taken; previous chest pain, respiratory problems, long haul travel (immobility), how long the pain has been present, what the pain is like, what triggers it, what relieves it, accompanying symptoms, shortness of breath, syncope, cough, wheezing, past medical history. Observation should be taken; respiratory rate/quality, BP, pulse, temperature (ECG is also useful). The Early Warning System should be used if in an acute setting.
Pleurisy is generally treated initially with NSAIDs (use with caution in those with asthma, as with those with gastric ulcers,, patients over 65 and those on aspirin, anti-coagulants, corticosteroids or SSRIs). Indomethacin given 50-100mg daily can improve lung function and relieve pleuritic pain in chronic cases. If NSAIDs are unsuitable, or not tolerated narcotic analgesia can be given but caution is essential as it can cause respiratory depression. It must also be considered that pleurisy is a symptom of an underlying condition requires prompt diagnosis and treatment.