Connective Tissue: Understanding the Link Between PF and Scleroderma

Last month, while collectively celebrating international Rare Disease Day, we received many questions about whether there is a link between PF and other rare diseases such as scleroderma. For many people living with pulmonary fibrosis (PF), the story doesn’t begin and end with the lungs. PF can sometimes be part of a larger autoimmune or connective tissue disease affecting multiple parts of the body. One of the most notable examples is scleroderma, a rare autoimmune disease that can affect the skin, blood vessels, digestive system, and the lungs. Understanding this connection matters, because identifying these diseases early can change how pulmonary fibrosis is diagnosed, monitored, and treated.

What Is Connective Tissue, and Why Does It Matter?

To understand why pulmonary fibrosis can occur alongside autoimmune diseases, it helps to understand connective tissue itself. Connective tissue is the body’s structural support system. It helps hold organs together, maintain elasticity, and support blood vessels, skin, joints, and internal organs. Much of connective tissue is made of proteins like collagen that provide strength and flexibility throughout the body.

Think of connective tissue as the highway or scaffolding of the body. When connective tissue is healthy, organs can stretch, repair, and function normally. But in connective tissue diseases, the immune system mistakenly attacks these structural tissues. This can lead to:

• Inflammation
• Fibrosis (scarring)
• Changes in blood vessels
• Damage to organs

Because connective tissue exists throughout the body, these diseases often affect multiple organ systems, including the lungs. Several connective tissue diseases are known to increase the risk of interstitial lung disease (ILD), the group of lung diseases that includes pulmonary fibrosis. These include:

• Scleroderma
• Rheumatoid arthritis
• Sjogren’s syndrome
• Lupus

Another notable condition that frequently appears in these diseases is Raynaud’s phenomenon. Raynaud’s causes the small blood vessels in the fingers and toes to narrow in response to cold or stress, leading to color changes, often turning white, blue/purple, and then red as circulation returns. 

While Raynaud’s can occur on its own, it is also one of the earliest warning signs of connective tissue disease for many people. In some cases, symptoms like Raynaud’s may appear years before lung disease is recognized. For people living with pulmonary fibrosis, recognizing these connections is important. PF may sometimes be the first visible sign of an underlying autoimmune disease, or it may develop later in the course of a connective tissue disorder.

Among these conditions, one of the strongest and most well-known links to pulmonary fibrosis is scleroderma, which we’ll explore in more detail below.

The Link Between Scleroderma and Pulmonary Fibrosis

Scleroderma is a rare autoimmune disease that causes excessive fibrosis (scarring) throughout the body. When this scarring affects the lungs, it can lead to interstitial lung disease, often called scleroderma-associated ILD. Lung involvement is extremely important in scleroderma because:

• A large portion of patients develop lung disease
• Lung fibrosis is one of the most serious complications of scleroderma
• Lung involvement may begin before noticeable breathing symptoms appear

This is why many experts recommend screening for lung disease even if patients are breathing well.

How Lung Disease Is Detected

Diagnosing lung disease related to connective tissue disorders involves several steps. Doctors often combine clinical exams, imaging, and breathing tests to understand what is happening in the lungs. One of the first clues may come from something simple: listening to the lungs.

Listening to Lung Sounds

During a physical exam, doctors use a stethoscope to listen to breathing sounds. In pulmonary fibrosis, they may hear distinctive sounds sometimes described as velcro-like “crackles.” These sounds can be an early sign of interstitial lung disease and may prompt further testing.

Pulmonary Function Tests (PFTs)

Pulmonary function tests measure how well the lungs are working by evaluating lung capacity, airflow, and oxygen exchange. These tests can detect changes in lung function even before symptoms become severe.

High-Resolution CT Scan (HRCT)

A high-resolution CT scan provides detailed images of lung tissue and can reveal early inflammation, patterns of lung scarring, and changes consistent with interstitial lung disease.

Signs That PF Might Be Connected to a Connective Tissue Disease

Sometimes pulmonary fibrosis is diagnosed first. Other times, autoimmune disease is diagnosed first. Certain symptoms may suggest a connective tissue disease connection, including:

• Color changes in fingers or toes in cold temperatures (Raynaud’s)
• Skin tightening or thickening
• Joint pain or swelling
• Severe acid reflux
• Dry eyes or dry mouth
• Puffy fingers or swollen hands
• Unexplained fatigue or brain fog

These symptoms can appear years before lung disease is recognized. If you notice patterns like these, it may be helpful to ask your doctor whether autoimmune evaluation or rheumatology consultation is appropriate.

What Patients Can Do Right Now

If you live with pulmonary fibrosis, or symptoms that might suggest it, there are several steps you can take.

Ask About Autoimmune Evaluation

If your PF diagnosis is described as “idiopathic,” you may want to ask about screening for connective tissue diseases. This may include autoimmune antibody tests, evaluation by a rheumatologist, or additional imaging or lung function testing.

Request Lung Screening if You Have Scleroderma

If you have scleroderma, ask your care team about routine lung monitoring, including pulmonary function tests (PFTs), imaging when appropriate, and regular follow-up with a pulmonologist. Early detection allows treatment to begin before severe lung damage develops.

Track Your Symptoms

Even small changes may matter. Keep track of:

• Inflammation 
• New or worsening cough
• Increasing shortness of breath
• Reduced exercise tolerance
• Fatigue or changes in stamina
• Sleep patterns or difficulties
• Digestive problems or concerns

Sharing these changes with your doctor can help identify lung disease earlier.

Build a Coordinated Care Team

Connective tissue diseases often require care from multiple specialists, such as pulmonologists, rheumatologists, cardiologists, gastroenterologists, and sleep specialists. Rare diseases rarely fit neatly into one specialty, so coordinated care is important.

Frequently Asked Questions

Is pulmonary fibrosis caused by scleroderma?

Sometimes. Pulmonary fibrosis can occur independently, but it can also develop as part of scleroderma-related lung disease. When PF occurs in people with scleroderma, it is usually called scleroderma-associated interstitial lung disease.

Is scleroderma hereditary?

Most cases are not directly inherited, although genetics may influence risk or susceptibility. Researchers believe environmental triggers, immune system abnormalities, and vascular changes all play roles.

If both diseases are rare, how can someone have two rare diseases?

This is a common and understandable question. In many cases, it isn’t actually two unrelated diseases. Instead, it may be one autoimmune condition affecting multiple organs. In this situation, pulmonary fibrosis is one manifestation of a broader disease process (scleroderma → connective tissue damage → lung fibrosis).

Can connective tissue-related lung disease be treated?

Treatments aim to slow disease progression, reduce inflammation, and manage symptoms. These may incorporate immunosuppressive medications, antifibrotic therapies, pulmonary rehabilitation, and oxygen therapy when needed. Early diagnosis often leads to more treatment options and better outcomes.

Moving Forward: Awareness That Leads to Action

Rare Disease Day reminded us that rare diseases are often more connected than we realize. Pulmonary fibrosis does not always occur by itself. In some patients, PF is part of a broader autoimmune condition affecting connective tissue throughout the body. Recognizing these connections can help patients and clinicians detect lung disease earlier and guide treatment decisions.

For the pulmonary fibrosis community, understanding links with connective tissue diseases like scleroderma – and early warning signs such as Raynaud’s – can help:

• Improve diagnosis
• Identify lung disease earlier
• Expand treatment options
• Strengthen research across rare diseases

Awareness can translate into something powerful: earlier testing, earlier treatment, and better outcomes. To learn more and connect with people who can relate, join our community forum and sign up for support group. To take action right now, please consider making a donation or becoming a volunteer. Learn more here.