Introduction

What is pleurisy?

Pleurisy occurs when the area around the lungs gets inflamed or irritated, causing strong chest pain, especially while breathing or coughing. It usually gets better within a few days, but sometimes it can be a sign of a more serious condition, like pneumonia. It is important to understand the causes of pleurisy, as it helps doctors treat it appropriately. Some causes are mild and easy to treat, while others, like infections or blood clots, can be serious and need urgent medical treatment. Understanding the cause ensures that the right treatment is given, which can prevent complications and aid faster recovery. Causes of pleurisy include viral infections (like influenza, and adenovirus), bacterial infections (like mycobacterium tuberculosis, pneumonia), and autoimmune conditions (like rheumatoid arthritis and systemic lupus erythematosus), and pulmonary embolism.

Infections as a cause of pleurisy

Viral infections

• Influenza (lu): the flu virus can infect the lining and the space between the lungs(the pleura), causing inflammation of the lungs. It can also cause sharp chest pain and breathing difficulties. In some cases, the infection may lead to complications like pneumonia, increasing the risk of pleurisy
• COVID-19: it can cause significant lung inflammation, which can reach the pleura, causing pleurisy and other symptoms like chest pain and respiratory distress
• Respiratory syncytial virus: it mostly affects the respiratory tract, but it can also cause inflammation of the pleural space, especially in young children and the elderly
• Adenovirus: although it is not a primary cause of pleurisy, it can contribute to its development if it causes an infection like pneumonia

Bacterial infections

• Pneumonia: Streptococcus pneumoniae, which causes pneumonia, can infect the lungs and spread to the pleura, inflaming the lungs and causing sharp chest pain and difficulty breathing
• Tuberculosis: Mycobacterium tuberculosis can infect the pleura leading to pleurisy. It can also cause other other symptoms like chronic cough, breathing difficulty, weight loss, and chest pain
• Staphylococcus aureus: This bacteria can cause lung infections. It is mostly found in hospital patients and this is mostly antibiotic-resistant bacteria
• Haemophilus influenzae: This bacteria can cause various respiratory infections, most commonly pneumonia, and bronchitis, and can lead to pleurisy

Autoimmune conditions

Rheumatoid Arthritis (RA)

• It is an autoimmune condition, therefore, it mistakenly attacks the body’s own tissues. These attacks mainly affect the joints and can harm the lining of the lungs, causing inflammation of the pleura
• RA causes inflammation, pain, and stiffness.  It can cause shortness of breath, heaviness in the chest, and reduced functioning of the lungs. Additionally, it also affects the skin and the eyes

In some cases, RA can cause pleural effusion which is the accumulation of the fluid in the pleural space. 

Systemic Lupus Erythematosus (SLE)

• In SLE the immune system also mistakenly attacks the body’s own healthy tissues
• This condition causes inflammation of the pleura leading to pleurisy
• In lupus patients, pleuritis leads to chest pain and shortness of breath
• In some cases, SLE induces pleuritis and may cause pleural effusion, resulting in breathing difficulties

Other autoimmune conditions

• Systemic sclerosis: Excessive collagen accumulation causes thickening and hardening of the skin and other organs, including the lungs. This can cause inflammation of the lungs, chest pain, and pleural effusion
• Sjogren’s syndrome: This condition is mostly associated with dryness of mouth and eyes, and can affect the lungs. This leads to breathing difficulties and a dry cough
• Ankylosing spondylitis: it primarily affects the spine, but can also affect the lungs and cause chronic inflammation
• Wegener’s granulomatosis: It affects blood vessels leading to inflammation of organs
• Polymyositis/dermatomyositis: It is an inflammatory muscle disease that causes muscle weakness. It affects several muscles, affecting those close to the trunk mainly, including the lungs. The muscles become irritated and eventually start to break down
• Goodpasture’s syndrome: This is a rare disease where the immune system attacks the basement membranes in the lungs and kidneys, leading to bleeding from the lungs and kidney failure. This can eventually result in death

Pulmonary embolism as a cause of pleurisy

• In pulmonary embolism, blood clots are formed due to the blocking of arteries in the lungs
• Obstruction in the blood flow to the lungs can lead to a shortage of oxygen supply to the tissues resulting in tissue damage
• In some cases, pulmonary embolism can cause pleural effusion, which can increase pressure on the lungs and cause other respiratory symptoms
• Dry cough, coughing up blood can be associated with pulmonary embolism which can worsen or damage the lung tissues leading to pleurisy

FAQs

Is pleurisy from autoimmune diseases chronic?

Pleurisy caused by autoimmune diseases can be chronic with symptoms resurfacing. It is important to manage autoimmune conditions effectively to control pleurisy.

How does pleurisy differ between viral and bacterial infections?

Viral pleurisy usually causes milder symptoms and often resolves on its own, while bacterial pleurisy tends to be more severe and may involve pleural effusion, requiring antibiotics and more intensive treatment.

Can a pulmonary embolism cause pleurisy?

Yes, a pulmonary embolism which forms blood clots in the lungs and causes damage to the lung tissues leads to lung inflammation and pleurisy.

Can pleurisy be treated at home?

Mild pleurisy especially caused by viral infections can be managed at home with painkillers, deep breathing exercises, and rest. However, persistent and severe symptoms require medical treatment.

Is pleurisy serious?

If pleurisy is caused by conditions like pulmonary embolism, bacterial infections, or autoimmune diseases then it can be serious. It is important to treat the underlying causes to prevent any complications.

How long does pleurisy last?

The duration of pleurisy varies depending on the cause. Pleurisy caused by viral infections may last a few days to weeks. Pleurisy from chronic conditions like rheumatoid arthritis or lupus may require a longer time to heal, potentially months.

Can pleurisy be prevented?

Pleurisy can be prevented by managing underlying conditions like autoimmune diseases, viral and bacterial infections, avoiding chest injuries, and taking early treatment for respiratory symptoms.

Can pleurisy be contagious?

Pleurisy itself is not contagious but some other underlying infectious conditions that cause pleurisy such as viral and bacterial infections may be contagious.

Summary

Pleurisy is an inflammation of the pleura, the membranes surrounding the lungs. It can have several causes like viral and bacterial infections, autoimmune disorders, and pulmonary embolism, among others. If the underlying cause is known, it can be treated and the symptoms can be managed. Depending on the cause, pleurisy can be mild and resolve on its own or require proper medical treatment.  It is important to seek medical attention if one has symptoms of pleurisy, which include shortness of breath, severe chest pain, and chronic cough.