What is systemic sclerosis?

Systemic sclerosis (SSc), often called scleroderma, is a long-term autoimmune condition that causes inflammation and scarring (fibrosis) in the skin and internal organs. The name comes from the Greek for hard skin, but the condition is much more than a skin disease. Fibrosis can affect the lungs, heart, kidneys, gastrointestinal tract, and other organs, and the consequences for these organs often determine the long-term outlook.

The two main forms.

Limited cutaneous SSc (lcSSc): skin involvement is limited to the hands, face, and below the knees and elbows. Internal organ involvement tends to develop slowly. Some patients develop pulmonary hypertension years after onset.

Diffuse cutaneous SSc (dcSSc): more extensive skin involvement, including the trunk and proximal limbs. Internal organ involvement (interstitial lung disease, renal crisis, cardiac involvement, gastrointestinal involvement) tends to develop earlier and more aggressively.

The initial features. Raynaud phenomenon (colour changes and discomfort in fingers and toes triggered by cold or stress) is often the earliest sign and may precede the other features by years. Skin thickening, swelling of the hands and fingers, gastroesophageal reflux, and joint stiffness are common early manifestations. Specific autoantibodies (anti-centromere, anti-Scl-70 / topoisomerase I, anti-RNA polymerase III) help define the form and predict patterns of organ involvement.

The traditional therapy. For decades, SSc had few specific therapies. Treatment was organ-specific: medications for Raynaud phenomenon, ACE inhibitors for renal crisis, immunosuppressants for skin or lung involvement, supportive care for gastrointestinal manifestations. There was no medicine specifically targeting the underlying autoimmune-fibrotic biology.

The modern therapy. Specific therapy options have expanded substantially in the past several years.

For SSc-associated interstitial lung disease (SSc-ILD): tocilizumab (an IL-6 receptor antagonist) has approval. Nintedanib (an antifibrotic medicine) has approval. These can be used alone or in combination with each other or with mycophenolate, depending on disease characteristics.

For severe diffuse skin disease: rituximab and intravenous immunoglobulin are options.

For severe refractory disease in selected patients: hematopoietic stem cell transplant has substantial evidence supporting its role.

For pulmonary hypertension associated with SSc: PAH-specific therapy applies, including the modern multi-pathway combination therapy described in earlier rounds.

For scleroderma renal crisis: ACE inhibitor (captopril traditionally) is the foundation; this is one of the most successful examples of a specific therapy transforming outcomes in SSc.

The emerging direction. Anifrolumab (an anti-type-I-interferon antibody) is in late-stage scleroderma trials. Novel B-cell-targeted programs, anti-fibroblast programs, and autotaxin pathway programs are in late-stage trials. Whether any of these can deliver true disease-modifying benefit in SSc is the central question for the next several years.

What to expect. SSc remains a serious condition, but modern multidisciplinary care substantially improves outcomes compared to the era when no specific therapy existed for most manifestations. Care at a scleroderma specialty clinic (rheumatology working with pulmonology, cardiology, gastroenterology, dermatology, and other specialists) delivers the most comprehensive approach. Long-term follow-up is the rule, and proactive surveillance for the organ manifestations of SSc is what catches problems early when they are most treatable.