Yes, scleroderma is an autoimmune disease. The immune system mistakenly produces antibodies that attack the body’s own connective tissue, triggering a chain reaction of inflammation, blood vessel damage, and excessive scarring (fibrosis) in the skin and, in some cases, internal organs. With a global incidence of roughly 86 new cases per million people per year, it is rare but serious, and it affects women significantly more often than men.
How the Immune System Goes Wrong
In a healthy immune system, B cells and T cells work together to fight infections and ignore the body’s own tissues. In scleroderma, that distinction breaks down. Environmental triggers and oxidative stress disrupt the normal balance between these immune cells, and B cells begin producing autoantibodies, proteins that target the body’s own cells instead of foreign invaders.
These autoantibodies attack the lining of blood vessels (endothelial cells) and the cells responsible for building structural tissue (fibroblasts). Once under attack, fibroblasts go into overdrive, producing far too much collagen, the protein that gives skin and organs their structure. The result is thick, hardened tissue that can restrict movement, reduce blood flow, and impair organ function. Researchers describe this process as a triad: immune activation, vascular damage, and excessive collagen production, all feeding into each other in a self-reinforcing loop. Some evidence also points to a faulty tissue-repair response as a fourth contributing factor.
Localized vs. Systemic Scleroderma
Scleroderma falls into two broad categories, and the distinction matters because they behave very differently.
Localized scleroderma stays in the skin and the muscles and tissues just beneath it. It typically appears in one of two patterns: oval-shaped patches of thick, firm skin (called morphea) or lines of thickened, discolored skin running down an arm, leg, or occasionally the forehead (called linear scleroderma). Localized scleroderma does not damage internal organs.
Systemic scleroderma (also called systemic sclerosis) is the more serious form. It affects blood vessels and can damage the heart, lungs, kidneys, and digestive tract. Systemic scleroderma itself is further divided into limited and diffuse types. The limited form progresses more slowly and tends to affect skin on the hands, face, and lower arms before potentially reaching internal organs years later. The diffuse form spreads faster and involves more widespread skin thickening along with earlier organ involvement.
Raynaud’s Phenomenon as an Early Sign
For many people, the first noticeable symptom is Raynaud’s phenomenon: fingers or toes that turn white or blue in response to cold or stress, then flush red as blood flow returns. Raynaud’s is extremely common on its own and is usually harmless. But when it appears alongside other changes, like puffy fingers, skin tightening, or difficulty swallowing, it can signal developing scleroderma.
Doctors distinguish between harmless (primary) Raynaud’s and the type linked to autoimmune disease (secondary Raynaud’s) by examining the tiny blood vessels at the base of your fingernails under a microscope. Damaged or abnormal capillaries there suggest an autoimmune process is already underway. Secondary Raynaud’s tends to be more severe and, in serious cases, repeated episodes can lead to skin sores or tissue damage at the fingertips.
Lung and Organ Involvement
The most dangerous complication of systemic scleroderma is lung disease. Depending on the population studied, anywhere from 26% to 88% of people with systemic sclerosis develop interstitial lung disease, a condition where scar tissue builds up in the lungs and makes it progressively harder to breathe. The wide range reflects differences in how aggressively doctors screen for it and how early in the disease they look.
Pulmonary arterial hypertension, where high blood pressure develops in the arteries connecting the heart and lungs, is another major concern. Both complications are leading causes of death in scleroderma, which is why lung function monitoring is a routine part of care.
The kidneys, heart, and gastrointestinal tract can also be affected. Kidney crises, though less common than they once were, can cause a sudden spike in blood pressure that requires urgent treatment. Digestive problems, including acid reflux and difficulty moving food through the intestines, are among the most frequent day-to-day complaints.
How Scleroderma Is Diagnosed
Diagnosis relies on a combination of physical examination, blood tests, and assessment of organ function. Blood tests look for specific autoantibodies that help confirm the diagnosis and predict which subtype a person has.
- Anti-centromere antibodies are found in about 32% of all scleroderma patients, but that number rises to 57% in people with the limited form. Their presence generally signals a slower disease course.
- Anti-Scl-70 antibodies (also called anti-topoisomerase I) appear in about 34% of all patients and roughly 40% of those with the diffuse form. They are associated with a higher risk of lung fibrosis.
- Anti-RNA polymerase III antibodies are linked to rapidly progressing skin involvement and kidney complications.
No single antibody is present in every patient, so doctors interpret these results alongside symptoms, skin changes, and imaging of the lungs and other organs.
Treatment and What to Expect
There is no cure for scleroderma, but treatment has improved substantially. The goal is to suppress the overactive immune response, slow fibrosis, and manage specific organ complications before they cause permanent damage.
Immunosuppressive medications remain the backbone of treatment for skin and lung involvement. These drugs dial down the immune system’s attack on healthy tissue. For patients with progressive lung scarring, an antifibrotic drug that slows collagen buildup has been shown to reduce the rate of lung function decline by about 41 milliliters per year compared to placebo, a meaningful difference in preserving breathing capacity over time.
When scleroderma causes pulmonary arterial hypertension, treatment typically involves a combination of drugs that relax and widen the blood vessels in the lungs. Current guidelines recommend starting with two classes of these medications together, which has improved both survival and quality of life compared to older single-drug approaches.
For a small number of patients with severe, rapidly progressing disease, stem cell transplantation using the patient’s own blood-forming cells is an option. It is the closest thing to a disease-modifying treatment available, essentially rebooting the immune system, but it carries significant risks and is reserved for people whose disease is aggressive enough to justify them.
Day-to-day management also includes physical therapy to maintain hand and joint mobility, protecting extremities from cold to manage Raynaud’s, and treating digestive symptoms. Because scleroderma varies so widely from person to person, treatment plans are highly individualized, and regular monitoring for new organ involvement is a permanent part of living with the disease.