What is pleurisy?

Your lungs are covered by two thin membranes called pleura that separate them from the chest wall. The layer that covers the lung's surface is called the visceral pleura, while the layer lining the inner wall of the chest cavity is called the parietal pleura. A space between these membranes is called the pleural space. In normal conditions, there is only a small amount of fluid in this space, which helps the pleura slide smoothly over each other during breathing.¹

When the pleura becomes inflamed, it is called pleurisy or pleuritis. A wide range of conditions can cause pleurisy, including viral and bacterial infections, cancer, chest wall trauma, pneumothorax, acute coronary syndromes, rheumatoid arthritis, tuberculosis, and mesothelioma. Pleurisy pain is unique; it is sharp, localised and worsens with breathing movements, sneezing, or coughing. This typical pain is known as pleuritic pain.²

Tuberculosis pleurisy

What is tuberculosis?

As mentioned above, pleurisy can occur due to various conditions, including tuberculosis. In general, tuberculosis is an infection that affects your lungs and is caused by a bacterium called Mycobacterium tuberculosis. This disease spreads through the air when an infected person coughs, sneezes, or spits, spreading droplets of the bacteria. However, not everyone infected with this bacterium will develop tuberculosis. Your immune system often fights off the infection; only 5-10% of people infected with TB will develop the disease and show symptoms.³

When the infection occurs in your lungs, it is called tuberculosis or pulmonary tuberculosis. However, Mycobacterium tuberculosis can infect other sites, such as lymph nodes (lymphatic TB), pleura (tuberculous pleurisy), and the membranes of the brain (tuberculous meningitis), among others. These conditions are called extrapulmonary tuberculosis.

Extrapulmonary tuberculosis usually occurs due to the spread of bacteria through the bloodstream from the initial site in the lungs or the reactivation of inactive bacteria outside the lungs. It can also occur from the spread of other infected organs, such as the lymph nodes, or by direct extension from nearby organs.⁴

How tuberculosis bacteria affects your pleura

Tuberculous pleurisy occurs when an infected area in your lung ruptures into the pleural space. When the bacteria enter the pleural space, your immune system, which has previously been exposed to tuberculosis bacteria, fights them. This reaction leads to inflammation of the pleural membranes and can potentially cause fluid accumulation (pleural effusion).⁵

Symptoms of tuberculosis pleurisy 

Here are symptoms that commonly present when you have tuberculosis pleurisy:^5,6

• Pleuritic chest pain
• Nonproductive cough
• Fever
• Night sweats
• Weight loss
• Feeling unwell (malaise)
• Difficulty breathing (dyspnea), especially if there is pleural effusion

Diagnosis

Medical history and physical examination

• Medical history: You will be asked about your current symptoms and any previous medical conditions that may be relevant. The doctor may also discuss your potential exposure to tuberculosis patients
• Physical examination: The doctor will check for signs such as fever, breathing rate, possible breathing difficulty, and pleuritic chest pain

Pleural fluid examination

Procedure: A sample of your pleural fluid will be taken using a thin needle inserted into your chest cavity. The analysis includes:

• Appearance or colour: Normally, the fluid is clear and yellowish (straw-coloured). In tuberculous pleurisy, it may become cloudy, indicating infection
• Cell type and cell count: Increased white blood cells, particularly lymphocytes, can indicate tuberculosis
• Biochemistry: Elevated levels of enzymes like adenosine deaminase and a substance called interferon-gamma (IFN-γ) can support the diagnosis

Radiology

• Chest X-ray: Usually reveals pleural effusion (fluid accumulation in the pleural space) at a small to moderate level
• Chest Computed Tomography (CT): Provides a more accurate visualisation of the pleura and lung tissue lesions, the presence of swollen lymph nodes, and other complications related to tuberculous pleurisy

Mycobacterial stain and culture

• Sputum: Thick mucus produced by your lungs that can help diagnose tuberculosis infections. Usually, the healthcare provider will ask you to collect it in the morning, and the sputum will be examined under a microscope. However, studies suggest that the sensitivity of sputum culture is quite low
• Pleural fluid: Just like sputum, pleural fluid can help detect acid-fast bacilli (AFB), which includes Mycobacterium tuberculosis

Pleural biopsy

A small sample of your pleura is taken and examined under a microscope. This can help identify tuberculosis bacteria and differentiate it from other causes of pleurisy, including cancer. However, a biopsy is not always necessary due to the associated risks.^5,7

Treatment

Anti-tuberculosis medication

In most cases that have no complications, the treatment will involve 4 regimens for 6 months, including:

• Isoniazid and Rifampicin: These two drugs are taken throughout the 6 months
• Pyrazinamide and Ethambutol: These are added for the first two months

Although tuberculous pleurisy can be treated with just Isoniazid and Rifampicin, the 4-drug regimen is recommended to prevent drug resistance. The average time for the resorption of pleural fluid is approximately 6 weeks but can extend to 12 weeks. Some patients may also develop pleural thickening.

Therapeutic thoracentesis

If pleural effusion (fluid accumulation in the pleural space) develops, it needs to be drained through a procedure called thoracentesis. This is crucial because excess fluid can cause breathing difficulties, and draining it can relieve symptoms. In some cases, a chest tube may be placed to allow continuous drainage of the fluid.

Corticosteroids

Corticosteroids are medications that relieve inflammation. Using corticosteroids for tuberculous pleurisy can help reduce pleural inflammation and may aid in fluid resorption. They can also prevent further damage to the pleural tissue, such as pleural thickening.

Intrapleural fibrinolytic

Some studies show that adding fibrinolytics to anti-TB medication can hasten the resolution of pleural effusion and reduce the incidence of pleural thickening. Fibrinolytics help break down fibrin, which can contribute to fluid accumulation and tissue thickening.^8,9

FAQs

What is the cause of tuberculous pleurisy?

Tuberculous pleurisy occurs when Mycobacterium tuberculosis bacteria reach the pleural space, usually due to the rupture of a small area of tuberculosis infection in the lung. When this happens, your body's immune system responds vigorously to the bacteria, causing inflammation of the pleura and sometimes resulting in fluid accumulation in that space (pleural effusion).¹⁰

Is tuberculous pleurisy contagious?

No, tuberculous pleurisy itself is not contagious. You cannot catch the disease directly from a person suffering from TB pleurisy. However, it's important to note that this condition is caused by Mycobacterium tuberculosis, a bacterium that is contagious. While tuberculous pleurisy, which involves the pleura, cannot spread from person to person, pulmonary tuberculosis, which affects the lungs and is caused by the same bacteria, can be spread when an infected person coughs or sneezes and spreads the droplets. 

What symptoms can TB in the lungs cause?

• Persistent cough for more than three weeks
• Productive cough (cough with mucus) may be bloody
• Fever
• Breathing difficulty
• Lose weight
• Night sweats¹¹

Is tuberculosis curable?

Yes, tuberculous pleurisy can be cured. The standard treatment involves a regimen of four antibiotics (isoniazid, rifampicin, pyrazinamide, and ethambutol) taken for six months. This treatment is typically effective and can cure tuberculosis in cases without complications.¹¹

Summary

• Tuberculous pleurisy is an inflammation of the pleura, which are the membranes that line the surface of the lungs and the inner wall of the chest cavity. It occurs when tuberculosis bacteria infect the lungs, leading to the rupture of a small infected site (locus) into the pleural space. This causes inflammation of the pleura and can result in fluid accumulation
• Symptoms of tuberculous pleurisy include pleuritic chest pain (pain worsens with breathing), cough, fever, night sweats, weight loss, malaise (feeling unwell), and dyspnea (difficulty breathing), especially when pleural effusion is present
• To diagnose tuberculous pleurisy, doctors typically take a thorough medical history, conduct a physical examination, and order tests such as chest X-ray, CT scan (if necessary), pleural fluid examination, and sputum/plural fluid stain and culture
• Treatment involves tuberculosis chemotherapy, which includes a regimen of antibiotics lasting several months to cure the infection. Additional treatments may include thoracentesis (draining pleural fluid if necessary), corticosteroids to reduce inflammation, and occasionally intrapleural fibrinolytic to aid in fluid resolution
• Prompt diagnosis and adequate treatment are crucial for curing tuberculous pleurisy and preventing further complications associated with the disease