Scleroderma is an autoimmune disease that causes inflammation and fibrosis (thickening) of the skin and other areas of the body. Hardening and tightening of the skin is the most common visible sign of scleroderma.  

Connective tissue is mostly made of collagen, a protein that makes scar tissue to repair the body after injury. Connective tissue gives structure and support to organs, like scaffolding. With scleroderma, the body produces extra collagen, causing more scar tissue to form in the skin. Derived from the Greek words sklerosis, meaning hardness, and derma, meaning skin, scleroderma literally translates to hard skin.  

Types of scleroderma 

There are two major forms of scleroderma.  

Localized scleroderma is a hardening of the skin that does not affect the internal organs. Typically, it affects only the skin but can also affect muscles.  

Systemic scleroderma or systemic sclerosis is a more serious condition that affects the skin, lungs, kidneys, heart, blood vessels, joints, muscles and gastrointestinal tract. It also can damage blood vessels and internal organs.  

The term systemic sclerosis refers to hardening that can occur in the internal organs. Most people with SSc also have Raynaud’s phenomenon. Raynaud’s causes decreased blood flow to fingers and toes. The decreased blood flow occurs because of spasms in fingers and toes when exposed to cold or stress. Some people can develop painful ulcers on their fingers or toes because of poor blood flow.  

Types of systemic scleroderma

There are two types of SSc. These are based on the degree of skin involvement.

Limted SSc or CREST Syndrome is more common and usually progresses more slowly than than diffuse SSc. Skin hardening typically affects lower arms and legs, as well as the face. Serious complications that affect the esophagus, other parts of the gastrointestinal track and lungs can occur.

Diffuse scleroderma or diffuse SSc progresses more rapidly and the hardening of the skin can occur throughout the body. People with diffuse scleroderma are more likely to have problems with their internal organs, including the digestive tract, kidneys, heart and lungs, early in the disease, while their skin is tightening quickly. This internal organ involvement usually differs from person to person.

If someone with SSc experiences shortness of breath and fatigue, they may have lung fibrosis or Group 1 PH (pulmonary arterial hypertension), a common complication of limited SSc. About 5% to 15% of people with SSc have PAH.  

Other forms of pulmonary hypertension can develop with SSc, including PH related to left heart disease, interstitial lung disease, chronic thromboembolic disease and pulmonary venous occlusive disease. Those conditions further complicate diagnosis and management.  

Annual screening for PAH is recommended for anyone with scleroderma regardless of symptoms. PAH causes the arteries to become stiff and narrow, making it difficult for the right side of the heart to pump blood through the lungs.  

People with SSc typically have problems exercising because of inflammation and stiffness in the joints, which cause pain. Let your doctor know if you have unexplained symptoms that affect physical ability, including:  

  • Shortness of breath with physical activity
  • Increased fatigue
  • Swelling of the ankles, legs, arms or stomach
  • Chest discomfort or pain
  • Light headedness or fainting with physical activity

PAH usually is treatable if diagnosed early enough. PAH is a serious and complex condition that requires immediate medical treatment and care. Although many people with Ssc lead long lives, pulmonary complications, including PAH and lung fibrosis, are the leading causes of death for people with SSc.  

Testing for PAH related to SSc

nnual screening for PAH will result in an earlier diagnosis. The sooner treatments begin, the better the outlook. Even when people with scleroderma aren’t being screened for PAH, they should always bring shortness of breath, swelling and other symptoms to a doctor’s attention. People with SSc should have these tests every year:

Echocardiogram

Pulmonary function tests

Ventilation-perfusion (V/Q) scan

Natriuretic peptide tests

Right heart catheterization

The goal is to diagnose PAH as early as possible before any symptoms occur. However, because of other medical conditions, it may be hard for a doctor to determine the cause of symptoms. For example, if a patient has shortness of breath while physically active, the cause could be an underlying lung fibrosis or PAH.

Many people who reduce their day-to-day activities to cope with new and increasing symptoms may forget to tell their doctors. Regular screening is the only reliable way to diagnose PAH early.

Diagnosing Pulmonary Hypertension

Learn more about PAH

  • Group 1: Pulmonary Arterial Hypertension

    Group 1 pulmonary hypertension is also known as pulmonary arterial hypertension. PAH occurs when the arteries in the lungs narrow and stiffen, leading to increased pressure in the lungs.

  • Diagnosing Pulmonary Hypertension

    Common symptoms, many causes and a variety of tests can make pulmonary hypertension difficult to diagnose. Knowing what symptoms to look for and diagnostic tests that provide critical information can lead to an earlier diagnosis and better outcomes.

  • Pulmonary Hypertension Care Centers

    PHA-accredited Pulmonary Hypertension Care Centers improve outcomes and quality of care for people with PH. Find expert care by locating a center or specialist near you.

Additional Resources

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Information on PH and Scleroderma is one of a series of PH& brochures available to download as a PDF or to order as a printed brochure. 

PH & Scleroderma