Lupus and the Respiratory System [March 2025 Update]

posted in Symptoms In Lupus on May 22, 2024 by

Gavin Abson

Updated March 1, 2025

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The respiratory system, or the pulmonary system, is commonly affected by systemic lupus erythematosus (SLE). This system plays a crucial role in exchanging gases, allowing us to absorb life-sustaining oxygen. Each system component contributes to breathing and oxygenation from the nose and mouth to the lungs and alveoli (microscopic air sacs that absorb oxygen). The lungs are one of the most commonly affected organs of the body.

This article discusses some of the ways that lupus affects the respiratory system.

“Pulmonary problems are so common in SLE that virtually all patients undergoing autopsy show lupus lung involvement.”

                  — Donald Thomas, MD, from The Lupus Encyclopedia: A Comprehensive Guide for Patients and Health Care Providers

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NOTE: Johns Hopkins University Press, publisher of The Lupus Encyclopedia, is a nonprofit publisher. If you purchase JHUP books, like The Lupus Encyclopedia, you support projects like Project MUSE.

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This blog post article was edited and contributed to by Donald Thomas, MD; author of “The Lupus Encyclopedia.” Parts of this blog post come from “The Lupus Encyclopedia: A Comprehensive Guide for Patients and Health Care Providers, edition 2.“

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Excerpt from “The Lupus Encyclopedia”

The respiratory system is also called the pulmonary system (pulmon- means “lung”). It begins at the nose and mouth, where you breathe air in and out, and continues down the major windpipe (trachea), which further branches out into smaller windpipes called bronchi and ends in the lungs. The last part of the lungs that the air reaches are tiny, microscopic sacs called alveoli. Alveoli have thin walls lined with small blood vessels called capillaries (see magnified view.

Oxygen from inhaled air is absorbed through the alveolar walls into the blood inside the capillaries. The blood entering the lungs by way of the pulmonary arteries, which come from the heart right ventricle (chapter 11), lacks oxygen. When inhaled oxygen is absorbed into these alveolar capillaries, the oxygen binds to hemoglobin (a protein that carries oxygen) in the red blood cells, causing the blood to become oxygenated. At the same time that oxygen is being absorbed, gases that the body does not need (such as carbon dioxide) are released. These unwanted gases travel from the alveolar capillaries into the air-containing portion of the lungs. When you breathe out, these gases leave the body.

Although SLE can affect any part of the respiratory system, the most common areas involved are lower respiratory areas. This includes the alveoli, the interstitium (tissue in between the alveoli), the blood vessels, and the outer lung lining (the pleura). Pulmonary problems are so common in SLE that virtually all patients undergoing autopsy show lupus lung involvement. 

Anatomy of the Respiratory System

The respiratory system starts at the nose and mouth. Because of this, nasal and oral ulcers (respectfully) are two of the most common respiratory problems seen in SLE patients. Other parts include the trachea (windpipe), bronchi (tubes leading from the trachea to the lungs), and finally, the lung tissues. At the microscopic level, tiny sacs in the lungs, called alveoli, absorb oxygen as we breathe in and exhale carbon dioxide as we breathe out.

Around the lungs is a lubricating sac called the pleural sac. The pleural sac is one of the serosa of the body. The body’s other two serosae are the pericardial sac (around the heart) and the peritoneal cavity (around the abdominal organs). SLE loves to cause inflammation within the serosa. Collectively, inflammation of the serosae is known as serositis. Inflammation of the pleural sac, called pleuritis and pleurisy, is one of the most common problems in SLE patients. See the section on pleuritis below.

Lupus-Related Complications

In SLE, inflammation and lung tissue damage can also affect the respiratory system. Common areas of involvement include the alveoli, interstitium, blood vessels, and pleura (as mentioned above). As a result, individuals with lupus may experience a range of respiratory symptoms and complications.

Respiratory Symptoms in Lupus

Respiratory symptoms associated with lupus can vary widely and may include:

• Shortness of breath
• Chest pain
• Coughing
• Wheezing
• Difficulty breathing deeply
• Pleuritic pain (pain with breathing)

Diagnosis and Management of Lupus-Related Respiratory Issues

Diagnosing the respiratory system’s involvement in lupus requires a thorough evaluation, including medical history, physical examination, imaging studies, and pulmonary function tests.

Treatment strategies aim to control inflammation, manage symptoms, and prevent complications. Treatment may involve medications such as hydroxychloroquine, biologics (like Benlysta and Saphnelo), corticosteroids, immunosuppressants (like methotrexate), and inhaler medications.

As of the date of writing this article, no official guidelines exist on managing lupus lung problems. However, the Sjogren’s Foundation published guidelines on Sjogren’s disease lung (pulmonary) involvement in 2021. Since Sjogren’s and lupus are closely related, many of these guidelines apply to lupus. The American College of Rheumatology also developed guidelines for managing interstitial lung disease (ILD). These are also useful in SLE patients who have ILD.

For example, if someone with lupus develops respiratory symptoms (like cough or shortness of breath), a high-resolution CAT scan of the chest and complete pulmonary function tests with diffusion capacity are the best diagnostic tools. Chest X-rays and spirometry (more commonly ordered tests) are inadequate for diagnosing many lung problems caused by lupus.

Complications and Prognosis

Complications such as pleurisy, pneumonitis, and pulmonary hypertension can significantly impact the quality of life when they cause symptoms such as shortness of breath and chest pain. These symptoms can cause great difficulty in doing essential daily tasks and lead to a poor quality of life. On the extreme, left inadequately treated, a dependence on oxygen and even death can occur. These severe complications can be averted in most patients with prompt diagnosis and treatment.

Navigating Respiratory Challenges in Lupus

If you have SLE and exhibit shortness of breath or chest pain, see a healthcare provider immediately. If these are new symptoms, consider going immediately to your closest Emergency Room.

Most patients should see their rheumatologist and a pulmonologist (lung expert). Since heart problems often cause symptoms similar to lung problems, like shortness of breath and chest pain, it is also usually prudent to see a heart specialist (cardiologist).

Excerpt from “The Lupus Encyclopedia: A Comprehensive Guide for Patients and Health Care Providers, edition 2” regarding lupus and the lungs

Chapter 10 of The Lupus Encyclopedia details how lupus affects the lungs, how they are diagnosed, and how they are treated. Below is an excerpt from the chapter:

Pleuritis (Pleurisy)

The Pleura

The “pleura” is the lining around the lungs. It consists of two thin layers of smooth, lubricated membranes. One layer envelops the lungs. The other attaches to the inside of the muscles and ribs around the lungs. Between these two layers is a light coating of lubricating fluid. When the lungs inflate and deflate during breathing, the lungs glide smoothly under the rib cage.

Lupus Serositis

Pleuritis refers to inflammation of the lung linings (pleura). Pleuritis occurs more often in men, patients with positive RNP, Smith, and dsDNA antibodies, and in patients with co-existing Raynaud’s (chapter 11). Patients with late-onset SLE (after 50 years old) also have an increased chance of developing pleuritis.

A similar type of lining exists around the heart (called the pericardium) and around the abdominal contents (called the peritoneum)—peri- means “around or about.” The medical term for these linings (pleura, pericardium, and peritoneum) is “serosa.” SLE can cause inflammation of the serosa, and the medical term for this is “serositis” (-itis means “inflammation of”). Serositis is part of the SLE classification criteria (chapter 1). When serositis occurs in the pleura, the medical term is “pleuritis” (also called “pleurisy”). Similarly, the medical term is “pericarditis,” when it occurs in the pericardium, and “peritonitis,” in the peritoneal lining.

Lupus serositis causes similar symptoms in these three areas. Healthy serosae (plural for serosa) allow the lungs, heart, and abdominal organs to move smoothly and effortlessly. During inflammation of the serosa, white blood cells enter the lining’s space. The lubricating fluid loses its smoothness, and the layers rubbing against each other become roughened. This can cause pain when that organ moves. Normally people are not conscious of their breathing, but every breath is noticeable with pleuritis because of the pain.

Pleurisy Symptoms

When chest pain worsens with breathing, the medical term is “pleuritic chest pain.” It is common in lupus pleuritis (and pericarditis, chapter 11). In addition to pleuritic chest pain, pleuritis can also cause shortness of breath, cough, and fever.

Other problems can also cause pleuritic chest pain (mimicking pleuritis). These include broken ribs, rib cartilage inflammation (costochondritis), sore ribs and muscles from poor posture, or other painful muscle problems such as fibromyalgia. A doctor must consider these other causes when evaluating chest pain that worsens with deep breathing.

How Pleurisy is Diagnosed

To sort out these possibilities, we begin with the physical exam. Tenderness of the chest wall suggests other causes (like costochondritis and fibromyalgia). Pleuritis can sometimes cause a “rub” when we listen to the lungs and heart. A rubbing sound occurs when friction from the inflamed pleura layers or pericardium scrape over each other (it sounds like two pieces of sandpaper rubbing each other).

The erythrocyte sedimentation rate and c-reactive protein ( ESR and CRP, inflammation tests, chapter 4) are usually elevated. Very high ESR and CRP levels in SLE patients are most commonly seen during infections, pericarditis, pleuritis, and aortitis (discussed farther down in this chapter). If the ESR and CRP are normal, then other causes of chest pain are more likely.

Diagnosis

A chest x-ray can look for fluid collection around the lungs. With pleuritis, the amount of extra fluid that occurs is often minimal, but sometimes there can be a large amount. This causes a pleural effusion ( “effusion” is a medical term meaning “a collection of fluid”).

The doctor often orders an ECG (electrocardiogram). This does not help diagnose pleuritis, but the ECG results may help diagnose pericarditis, the other type of lupus serositis that can cause pleuritic chest pain.

Pleuritis (pleurisy) is the most common SLE lung problem, occurring in 40% to 60% of patients. Yet, many SLE patients never notice they have it. We know this because autopsies of SLE patients show that up to 90% have had pleuritis at some point. Although pleurisy can be painful and cause shortness of breath, it rarely causes significant damage since it occurs outside the lungs.

If there is a pleural effusion, a doctor can sometimes drain the fluid (a procedure called thoracentesis). The doctor numbs up the chest wall muscles and skin, then inserts a needle through the numbed-up area and into the fluid to drain out the fluid. Laboratory analysis helps determine the cause of the pleural effusion. This is typically not needed in SLE patients. Thoracentesis is most useful the first time someone has a pleural effusion and its cause is unknown. Other possible causes include other systemic autoimmune diseases (such as rheumatoid arthritis), infections, cancer, and kidney or liver failure. The pleural fluid will have different lab findings depending on the cause.

Pleurisy Treatments

Sometimes, thoracentesis is needed for treatment, rather than for diagnosis. If someone has a large pleural effusion and trouble breathing, a thoracentesis can help them breathe much better.

Lupus pleuritis is usually treated with anti-inflammatory medicines. For mild cases, non-steroidal anti-inflammatory drugs (NSAIDs, chapter 36) such as naproxen may be used. Steroids may be necessary in more severe cases (in which the person has severe pain or when a large pleural effusion is present). Recurrent pleuritis attacks usually respond well to hydroxychloroquine. On occasion, stronger immunosuppressants are necessary.

On rare occasions, pleural fluid may not respond to the above. In this case, pleurodesis (pleuro- from the Greek for “rib or side” and -desis from the Greek desmos for “bond”) can be performed. Pleurodesis creates scar tissue within the pleura by injecting chemicals or talc or by scraping it. This scarring binds the outer lung surface to the inner ribcage, preventing fluid accumulation.

KEY POINTS TO REMEMBER

1. Pleuritis (also called pleurisy) is the most common lupus lung problem.
2. Most of the time, pleuritis causes no symptoms or problems.
3. The most common symptoms include pleuritic chest pain (pain with deep breathing), cough, and shortness of breath.
4. The initial treatments for are NSAIDs, steroids, and/or hydroxychloroquine (Plaquenil), but sometimes other immunosuppressants are needed.
5. If there is a lot of fluid around the lungs (pleural effusion), it may need drained by thoracentesis.

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For more in-depth information on Lupus and the Respiratory System [March 2025 Update]:

Read more in The Lupus Encyclopedia, edition 2

Look up your symptoms, conditions, and medications in the Index of The Lupus Encyclopedia

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