Systemic scleroderma is a rare autoimmune condition that causes the body to produce too much collagen, leading to hardening and thickening of skin and internal organs. While there is no cure, understanding the disease and working with healthcare specialists can help manage symptoms and improve quality of life.
What is Systemic Scleroderma?
Systemic scleroderma, also known as systemic sclerosis, is a rare disease that affects how your body produces tissue. The name comes from Greek words meaning “hard skin,” which describes one of the most visible features of the condition. In systemic scleroderma, your body makes too much of a protein called collagen, which normally helps keep your skin and other tissues strong and healthy. When there is too much collagen, your skin and other tissues become thicker and harder than they should be, almost like scar tissue.[1][2]
This condition is an autoimmune disorder, which means your immune system—the part of your body that normally protects you from germs and illness—makes a mistake and attacks your own body instead. Scientists don’t fully understand why this happens, but it’s as if your immune system can no longer tell the difference between what belongs in your body and what doesn’t. This confusion triggers cells to produce excessive amounts of collagen, causing the characteristic thickening and hardening of tissues.[2][4]
Unlike localized scleroderma, which only affects the skin in certain areas, systemic sclerosis can affect multiple parts of your body. It may impact your skin, but it can also affect internal organs such as your lungs, heart, kidneys, digestive system, and blood vessels. This widespread involvement is what makes systemic scleroderma more serious than its localized counterpart. The condition is chronic, meaning it lasts for a long time and requires ongoing management, sometimes for the rest of a person’s life.[1][3]
Types of Systemic Scleroderma
Healthcare providers divide systemic sclerosis into different types based on which parts of the body are affected and how extensively. The main types include limited cutaneous systemic sclerosis, diffuse cutaneous systemic sclerosis, and systemic sclerosis sine scleroderma. Each type has different patterns of symptoms and may affect different organs.[3][6]
Limited cutaneous systemic sclerosis is the most common form. In this type, skin thickening usually affects only certain areas of the body—typically the face, neck, hands below the elbows, and feet below the knees. This form is often called CREST syndrome, an acronym that stands for its five main features: Calcinosis (calcium deposits under the skin), Raynaud’s phenomenon (color changes in fingers and toes), Esophageal dysfunction (problems swallowing), Sclerodactyly (tight skin on fingers), and Telangiectasia (small red spots on skin from widened blood vessels). Limited disease tends to progress more slowly than other forms, though it can still affect internal organs, especially the lungs, over time.[2][3]
Diffuse cutaneous systemic sclerosis is less common but generally more severe. In this form, skin thickening spreads more widely across the body, affecting not just the hands and feet but also the arms above the elbows, legs above the knees, chest, abdomen, and back. Diffuse disease tends to worsen more quickly and is more likely to involve internal organs early in its course. People with diffuse systemic sclerosis have a higher risk of serious complications affecting the lungs, kidneys, heart, and digestive system.[2][6]
Systemic sclerosis sine scleroderma is an unusual form where internal organs are affected but the skin remains normal. People with this type may have Raynaud’s phenomenon and other internal symptoms characteristic of scleroderma, but they don’t experience the skin thickening that gives the disease its name. This can make diagnosis more challenging because the most visible sign of the condition is absent.[2][4]
Epidemiology: Who Gets Systemic Scleroderma?
Systemic scleroderma is a rare condition. Studies estimate that it affects somewhere between 50 and 300 people per million in the population. Because it is uncommon, many people have never heard of it before receiving a diagnosis, which can make the experience particularly frightening and isolating.[4][2]
The disease shows a strong preference for women. Women are approximately four times more likely to develop systemic sclerosis than men. Most people who develop the condition are diagnosed between the ages of 30 and 50, though it can occur at any age. Children can also develop systemic sclerosis, though this is rare. When the disease affects young people, it can be especially challenging as they face a chronic condition during important life stages—education, career building, and family planning.[4][1]
The reasons for these demographic patterns are not fully understood. Scientists believe that hormonal factors may play a role in why women are affected more often, but the exact mechanisms remain unclear. Geographic and ethnic variations in disease prevalence have also been observed, with some populations showing higher rates than others, though systemic scleroderma occurs in people of all ethnic backgrounds around the world.[4]
What Causes Systemic Scleroderma?
The exact cause of systemic scleroderma remains unknown, which is frustrating for both patients and doctors. What scientists do know is that the disease involves a complex interaction of genetic factors, environmental triggers, and immune system dysfunction. No single cause has been identified, and it appears that multiple factors must come together for the disease to develop.[3][4]
Genetics play a role in susceptibility to systemic sclerosis. Certain genes, particularly those in the human leukocyte antigen (HLA) complex—a group of genes that help the immune system distinguish between the body’s own proteins and foreign invaders—have been associated with increased risk. If you have a close family member with systemic sclerosis, your risk of developing the condition is higher than that of the general population, though most people with scleroderma do not have affected relatives.[4]
Environmental factors may also contribute to disease development. Exposure to certain substances has been linked to increased risk of scleroderma. These include silica dust (found in mining, sandblasting, and construction work), certain solvents, and some medications. However, most people exposed to these substances never develop scleroderma, suggesting that environmental triggers alone are not sufficient to cause the disease—a person must also have the right genetic susceptibility.[4]
The disease process itself involves three main problems: damage to blood vessels (vasculopathy), dysfunction of the immune system, and excessive tissue scarring (fibrosis). Scientists believe the process may begin with damage to the cells lining blood vessels. This damage triggers inflammation and activates the immune system, which produces autoantibodies—immune proteins that mistakenly target the body’s own tissues. These autoantibodies and the ongoing inflammation stimulate cells called fibroblasts to produce too much collagen, leading to the characteristic thickening and hardening of tissues.[3][4]
Risk Factors for Developing Systemic Scleroderma
Understanding risk factors can help identify people who may be more likely to develop systemic sclerosis, though having risk factors does not mean a person will definitely get the disease. The strongest risk factors relate to demographic characteristics, family history, and environmental exposures.[4]
Being female is one of the most significant risk factors. As mentioned earlier, women are four times more likely than men to develop systemic sclerosis. Age is also important—the disease most commonly begins in middle adulthood, though it can occur at any age. Having a family member with scleroderma or another autoimmune disease increases risk, suggesting inherited genetic factors contribute to susceptibility.[4][1]
Certain occupational and environmental exposures have been linked to increased risk. People who work with silica dust—such as miners, construction workers, and sandblasters—appear to have higher rates of scleroderma. Exposure to certain organic solvents, particularly those used in industrial settings, has also been associated with the disease. Some medications have been implicated as possible triggers, though this is rare. Additionally, there is evidence that having an underlying cancer may, in some cases, trigger the development of scleroderma-like symptoms.[4]
It’s important to understand that these are statistical associations, not guarantees. Most people with these risk factors never develop systemic sclerosis, and some people develop the disease without any known risk factors. This unpredictability is one of the challenging aspects of autoimmune diseases—they often strike seemingly at random, affecting otherwise healthy people.[4]
Symptoms of Systemic Scleroderma
The symptoms of systemic scleroderma vary greatly from person to person, depending on which parts of the body are affected and how severe the disease is. Some people have relatively mild symptoms that mainly affect their skin, while others experience serious problems with internal organs. Understanding the range of possible symptoms can help people recognize the condition and seek appropriate medical care.[1][5]
One of the earliest and most common symptoms is Raynaud’s phenomenon, which affects more than 80% of people with systemic sclerosis. In Raynaud’s, the small blood vessels that carry blood to the fingers and toes constrict excessively in response to cold temperatures or stress. This causes the affected areas to change color—typically turning white, then blue, and finally red as blood flow returns. During these episodes, fingers and toes may feel cold, numb, tingly, or painful. In severe cases, poor blood flow can lead to painful sores or ulcers on the fingertips. Raynaud’s can occur weeks or even years before other symptoms of scleroderma appear.[1][4]
Skin changes are another hallmark of systemic sclerosis. Early on, people may notice swelling and puffiness in their hands and fingers. The skin may feel itchy or uncomfortable. Over time, the skin becomes thicker, harder, and tighter—a process called sclerosis. The affected skin may look shiny and feel tough to the touch. It can become difficult to bend fingers fully or make a fist when the skin on the hands is affected. Facial skin involvement can limit the ability to open the mouth wide. The color of affected skin may change, becoming lighter or darker than normal. Some people develop small red spots on their skin called telangiectasias, which are tiny widened blood vessels visible near the surface.[1][4]
Many people with systemic sclerosis develop hard lumps under the skin, particularly at the fingertips and near joints. These are calcium deposits, a condition called calcinosis. While not usually dangerous, these deposits can be uncomfortable and sometimes break through the skin, causing sores that are slow to heal.[1][4]
Joint symptoms are common in systemic scleroderma. People may experience pain, stiffness, and swelling in their joints, particularly in the hands, wrists, knees, and ankles. The skin tightening itself can restrict joint movement, making it difficult to perform everyday tasks like buttoning clothes or writing. Some people develop inflammation of the tendons or muscles, causing additional pain and weakness.[5][8]
When systemic sclerosis affects internal organs, symptoms can be more serious. The digestive system is frequently involved. The most common digestive symptom is heartburn, which occurs when the muscle that connects the esophagus (food pipe) to the stomach doesn’t work properly, allowing stomach acid to back up. People may have difficulty swallowing, especially solid foods. The intestines can also be affected, leading to bloating, cramping, diarrhea, constipation, and difficulty absorbing nutrients from food.[1][4]
Lung involvement is a serious complication of systemic sclerosis. The lungs can develop interstitial lung disease, where the tissue between the air sacs becomes thick and scarred, making it harder to breathe. People may experience shortness of breath, especially during physical activity, and a persistent dry cough. Another lung complication is pulmonary arterial hypertension, where blood pressure in the arteries of the lungs becomes abnormally high, straining the heart and causing severe shortness of breath and fatigue.[5][8]
Heart problems can develop, including inflammation of the sac surrounding the heart (pericarditis), abnormal heart rhythms, and heart failure. The kidneys can also be affected, sometimes suddenly and severely in a complication called scleroderma renal crisis, characterized by sudden high blood pressure and rapidly declining kidney function.[1][5]
Other symptoms may include dry mouth and eyes, dental problems, muscle pain and weakness, and severe fatigue. The combination and severity of symptoms differ for each person, making systemic sclerosis a highly individual disease. Some people have relatively stable disease that changes little over time, while others experience rapid progression with significant disability.[5][7]
Prevention of Systemic Scleroderma
Unfortunately, because the exact causes of systemic scleroderma are not fully understood, there is no known way to prevent the disease from developing. Unlike some illnesses where lifestyle changes or vaccinations can reduce risk, systemic sclerosis appears to arise from a combination of genetic susceptibility and environmental factors that cannot be easily controlled or avoided.[2]
However, for people already diagnosed with systemic sclerosis, there are important steps that can help prevent complications and slow disease progression. These preventive measures focus on protecting organs from damage and managing symptoms before they become severe.[5]
For those with Raynaud’s phenomenon, preventing episodes is important for protecting fingers and toes from damage. This means keeping the entire body warm, not just the hands and feet. Wearing layers of clothing in cold weather, using insulated gloves and boots, and avoiding sudden temperature changes can all help. It’s also important to avoid activities that could injure the fingers or toes, as the reduced blood flow makes healing more difficult. Some people need to avoid certain medications, such as those containing pseudoephedrine (found in some cold medicines), because these can trigger Raynaud’s episodes by constricting blood vessels.[5][7]
Protecting the skin is another preventive measure. Keeping skin moisturized can help reduce itching and prevent cracking, which could lead to infections. Using gentle soaps and avoiding harsh chemicals or extreme temperatures can protect sensitive skin.[7]
For digestive symptoms, dietary changes can prevent problems before they start. Eating smaller, more frequent meals instead of three large ones can reduce heartburn. Avoiding foods that trigger acid reflux—such as spicy foods, caffeine, alcohol, and chocolate—and not eating close to bedtime can also help. Elevating the head of the bed can prevent stomach acid from backing up during sleep.[7][9]
Regular exercise and physical therapy can help maintain joint flexibility and muscle strength, preventing the stiffness and weakness that can develop when movement becomes limited. Gentle stretching exercises and activities like swimming or walking can be beneficial.[7]
Perhaps most importantly, regular medical monitoring can catch organ complications early, when they are most treatable. This includes periodic testing of lung function, heart function, kidney function, and blood pressure. Vaccinations are also important to prevent infections that could be more dangerous for people with autoimmune diseases and those taking immune-suppressing medications. Healthcare providers typically recommend vaccines for influenza, pneumonia, shingles, and other preventable diseases.[9][17]
Pathophysiology: What Happens in the Body
Understanding what happens inside the body during systemic sclerosis can help explain why the disease causes such varied symptoms. The disease process involves three interconnected problems: blood vessel damage, immune system dysfunction, and excessive collagen production leading to fibrosis.[3][4]
The process appears to begin with injury to the cells that line the inside of blood vessels, called endothelial cells. Scientists aren’t certain what causes this initial damage, but it may involve genetic factors, environmental triggers, or both. When these cells are damaged, they release chemical signals that attract immune cells to the area and trigger inflammation. This inflammation causes the blood vessels to become narrower and less flexible, reducing blood flow to tissues. Reduced blood flow means less oxygen and fewer nutrients reach the affected areas, which can damage tissues and trigger further inflammation.[3][4]
The immune system response in systemic sclerosis is complex and dysfunctional. The immune system produces autoantibodies—proteins that normally would attack foreign invaders but instead target the body’s own tissues. Different types of autoantibodies are associated with different forms of scleroderma. For example, people with limited disease often have anti-centromere antibodies, while those with diffuse disease may have anti-topoisomerase (Scl-70) antibodies or anti-RNA polymerase antibodies. These autoantibodies appear to play a role in perpetuating the disease process, though exactly how remains an active area of research.[3][4]
The combination of blood vessel damage, reduced blood flow, and chronic inflammation activates cells called fibroblasts. These cells normally produce collagen in response to injury, helping wounds heal. In systemic sclerosis, however, the fibroblasts become overactive and produce far too much collagen. This excessive collagen accumulates in the skin and organs, causing them to become thick, stiff, and scarred—a process called fibrosis. Unlike normal scar tissue that forms after an injury and then stops, the fibrosis in scleroderma continues to progress, potentially affecting more and more tissue over time.[2][4]
When fibrosis affects the skin, it causes the characteristic hardening and tightening that gives the disease its name. When it affects internal organs, the consequences can be serious. In the lungs, fibrosis makes the tissue stiff and less able to transfer oxygen into the blood, causing shortness of breath. In the digestive tract, fibrosis can interfere with the normal muscle contractions that move food through the system, leading to digestive problems. In the heart, it can affect the heart’s ability to pump effectively. In the kidneys, it can impair their filtering function.[1][8]
The blood vessel problems in scleroderma extend beyond the initial endothelial damage. Over time, the walls of small arteries can become thick and narrow, further reducing blood flow. This is particularly problematic in the lungs, where it can lead to pulmonary arterial hypertension—abnormally high blood pressure in the lung arteries that makes the heart work harder and can eventually lead to heart failure.[8]
These three processes—vasculopathy, immune dysfunction, and fibrosis—interact and reinforce each other in a vicious cycle. Blood vessel damage triggers inflammation, inflammation activates the immune system, the immune response promotes fibrosis, and fibrosis further damages blood vessels. Breaking this cycle is one of the main goals of treatment, though no therapy currently available can completely stop the process.[3][4]
