Systemic sclerosis, also known as scleroderma, is a rare and chronic autoimmune disease defined by the hardening and tightening of the skin and connective tissues. This condition arises when the immune system mistakenly attacks healthy tissues, leading to an overproduction of collagen. The result is a thickening and scarring process that can affect the skin, internal organs, blood vessels, and the digestive tract.
The Two Primary Forms
Systemic sclerosis is categorized into two main subtypes, distinguished by the extent of skin involvement. The first form is Limited Cutaneous Systemic Sclerosis (lcSSc), where skin thickening is restricted to areas like the hands, forearms, feet, lower legs, and face. This type often progresses slowly, and individuals may experience symptoms for years before more significant changes occur.
A well-known presentation of lcSSc is often referred to by the acronym CREST syndrome, which outlines a cluster of symptoms:
- Calcinosis, the formation of calcium deposits under the skin
- Raynaud’s phenomenon, where fingers and toes change color from cold
- Esophageal dysmotility, causing swallowing difficulties and heartburn
- Sclerodactyly, the tightening of skin on the fingers
- Telangiectasias, small, dilated blood vessels on the skin
The second primary form is Diffuse Cutaneous Systemic Sclerosis (dcSSc). In this type, skin thickening is more widespread and can affect the trunk, upper arms, and thighs. The onset of dcSSc is often more rapid, and there is a greater likelihood of significant involvement of internal organs early in the disease course, such as the lungs, heart, and kidneys.
Signs and Bodily Impact
The manifestations of systemic sclerosis are diverse, often beginning with the skin and blood vessels. One of the most common initial signs is Raynaud’s phenomenon, an exaggerated response to cold or stress where the small blood vessels in fingers and toes constrict. This causes the digits to turn white, then blue, and finally red upon rewarming, often accompanied by numbness or pain. Severe Raynaud’s can lead to fingertip sores or tissue damage from restricted blood flow.
Nearly all individuals with systemic sclerosis experience changes in their skin. The process starts with swelling and puffiness in the fingers and hands, progressing to a stage where the skin becomes tight and hardened. This thickening, known as sclerodactyly in the fingers, can restrict joint movement and may alter facial appearance. Some people also develop calcinosis, which are hard, painful calcium deposits under the skin, often near joints.
Beyond the skin, the disease frequently impacts the gastrointestinal tract. Esophageal dysmotility, a condition where the muscles of the esophagus do not contract properly, is common and leads to difficulty swallowing and chronic acid reflux (heartburn). In the lower digestive tract, the condition can cause problems with nutrient absorption, bloating, constipation, or diarrhea due to altered intestinal muscle function.
The lungs are another target of systemic sclerosis. Scarring of the lung tissue, a condition called pulmonary fibrosis, can develop and lead to shortness of breath with physical activity. Another serious complication is pulmonary hypertension, which is high blood pressure in the arteries of the lungs. This condition forces the right side of the heart to work harder.
The heart and kidneys can also be affected. The heart muscle can develop scarring, leading to abnormal heart rhythms or heart failure. A serious kidney complication known as scleroderma renal crisis can occur, characterized by a sudden increase in blood pressure and rapid kidney failure. Prompt treatment can often control blood pressure and preserve kidney function.
Understanding the Causes and Risk Factors
The precise origin of systemic sclerosis remains unknown, but research points to a complex interplay of three processes. The first is an autoimmune response, where the body’s immune system attacks its own healthy tissues. This is followed by vascular damage to small blood vessels. The third component is fibrosis, the excessive production of collagen, which leads to the characteristic thickening and scarring.
While a definitive cause has not been identified, several factors are associated with an increased risk. Genetics appears to play a role, as having a family member with an autoimmune disease can increase susceptibility. However, the disease rarely runs directly in families.
Environmental exposures are also thought to be potential triggers in genetically predisposed individuals. Occupational exposure to silica dust has been identified as a risk factor. Certain organic solvents and other chemicals have also been investigated for their potential role in triggering the disease.
Demographic factors also influence risk. Systemic sclerosis is significantly more common in women than in men, with a ratio of about 7 to 1. The age of onset is between 30 and 50 years old, suggesting that hormonal and age-related factors may contribute.
The Diagnostic Process
Diagnosing systemic sclerosis is a comprehensive process, as there is no single definitive test. Physicians rely on a combination of clinical evaluation, medical history, and specific lab tests. The process begins with a physical examination, focusing on characteristic skin changes like thickening and puffiness, especially in the fingers and hands.
A review of the patient’s medical history provides important clues. The presence of symptoms like Raynaud’s phenomenon, heartburn, difficulty swallowing, or shortness of breath is noted. The physician will ask about the onset and progression of these symptoms to build a complete clinical picture.
Blood tests are a key component of the diagnostic workup, as they can reveal specific autoantibodies strongly associated with systemic sclerosis. More than 90% of patients have antinuclear antibodies (ANA). More specific antibodies, such as anti-centromere antibodies (often found in limited disease) and anti-Scl-70 or anti-RNA polymerase III antibodies (more common in diffuse disease), can help classify the subtype and predict potential organ involvement.
To assess the extent of the disease and check for internal organ involvement, additional tests are used. A skin biopsy can confirm the presence of excess collagen. Imaging studies like high-resolution computed tomography (CT) scans and echocardiograms evaluate the lungs and heart, while pulmonary function tests measure breathing capacity.
Approaches to Management
As there is no cure for systemic sclerosis, treatment focuses on managing symptoms, slowing progression, and maintaining physical function. Management is tailored to the individual’s symptoms and organ involvement, often requiring a multidisciplinary team of specialists. The approach combines medication, therapy, and lifestyle adjustments.
Medications are used to target the disease’s three components: immune system overactivity, blood vessel problems, and organ-specific complications. To address the autoimmune response, immunosuppressive drugs such as mycophenolate mofetil or methotrexate may be prescribed. These help reduce inflammation and slow the progression of skin thickening and lung fibrosis.
For vascular issues like Raynaud’s phenomenon, medications that improve blood flow are used. Calcium channel blockers are often prescribed to relax and open up the small blood vessels, reducing attacks. In more severe cases involving digital ulcers, other drugs that dilate blood vessels, such as phosphodiesterase-5 inhibitors, may be administered.
Treatments are also directed at specific organ complications. For gastrointestinal symptoms like acid reflux, proton pump inhibitors are effective in reducing stomach acid. Angiotensin-converting enzyme (ACE) inhibitors are a primary treatment for scleroderma renal crisis. For lung fibrosis, antifibrotic medications or immunosuppressants may be used to slow the decline in lung function.
Non-pharmacological approaches are also a large part of management. Physical and occupational therapy play a significant role in maintaining joint mobility and function, especially in the hands, through stretching and strengthening exercises. Patients are advised on skin care, including regular moisturizing to combat dryness. Lifestyle advice, such as avoiding cold exposure and quitting smoking, is also important for managing Raynaud’s phenomenon.