Scleroderma is a chronic autoimmune connective tissue disorder characterized by the excessive production and accumulation of collagen, leading to the hardening and thickening of the skin and internal organs (fibrosis). This systemic disease, also known as systemic sclerosis, often affects the musculoskeletal system, making joint pain and stiffness common complaints. While there is no known cure, treatment focuses on managing these symptoms to improve a patient’s quality of life.
The Spectrum of Joint Involvement
Joint pain, or arthralgia, is a highly prevalent symptom in individuals with scleroderma, affecting up to 80% of patients at some point in the disease course. The joint symptoms can manifest in two primary ways: non-inflammatory pain (arthralgia) or true inflammatory joint disease (arthritis).
Arthralgia refers to joint pain without clinical signs of inflammation, such as swelling or redness, and it is the more common complaint. Inflammatory arthritis involves synovitis, which is the inflammation of the joint lining, leading to joint swelling and tenderness, particularly in the hands and wrists. In some patients, this inflammatory arthritis may be the first symptom of scleroderma, preceding the characteristic skin changes.
The Pathological Basis of Joint Pain
The underlying mechanisms causing musculoskeletal symptoms involve both the hallmark fibrosis and the autoimmune inflammatory response. The overproduction of collagen within connective tissues surrounding the joints leads to significant tissue hardening. This excessive fibrosis restricts the movement of joints and surrounding tendons, causing intense stiffness and pain.
This fibrotic process results in joint contractures, where joints become fixed in a bent position due to the tightening of skin and soft tissues. This mechanical restriction is a major source of functional limitation and chronic pain, especially in the hands. Separately, the autoimmune nature of the disease triggers inflammation that affects the joint lining, leading to synovitis and a traditional arthritis-like pain.
Secondary issues also contribute to pain and stiffness. The immune system can target muscle tissue, resulting in muscle weakness and pain (myopathy or myositis) that affects joint function. Furthermore, the deposition of calcium crystals (calcinosis) can occur in soft tissues near the joints, causing painful, hard bumps that interfere with movement.
Scleroderma Joint Features Compared to Other Arthritis
Joint involvement in scleroderma presents with characteristics that help distinguish it from other common forms of arthritis, such as Rheumatoid Arthritis (RA) or Osteoarthritis (OA). A defining feature is the presence of contractures—fixed joint limitations caused by the tightened, thickened skin and fibrotic tissues. This skin-driven restriction, known as sclerodactyly when it affects the fingers, is far less prominent in other inflammatory or degenerative joint conditions.
Scleroderma arthritis often affects the same joints as RA, like the wrists and small joints of the hands, but it is generally considered less destructive to the bone structure. True erosive arthritis (where bone is damaged) is less common than in advanced RA, though it can occur, particularly in overlap syndromes. Joint pain in scleroderma can also involve tendon friction rubs—a grating sensation felt over tendons—which is highly suggestive of the disease and rarely seen in other rheumatologic conditions.
The distinction between inflammatory arthritis and mechanical restriction is important for treatment planning. Inflammatory presentations with swelling are more likely to respond to anti-inflammatory medications, similar to RA. Conversely, pain and stiffness caused by contractures require intervention focused on improving tissue elasticity and range of motion.
Treatment Strategies for Musculoskeletal Symptoms
Management of musculoskeletal symptoms is tailored to whether the pain is primarily inflammatory or mechanical due to fibrosis. For mild joint pain or non-inflammatory arthralgia, pain relievers like acetaminophen or non-steroidal anti-inflammatory drugs (NSAIDs) may be used. If true inflammatory arthritis is present, treatment often includes low-dose corticosteroids (usually limited to less than 15 mg per day) to reduce inflammation.
For patients with persistent or severe inflammatory arthritis, disease-modifying anti-rheumatic drugs (DMARDs) are often introduced. Weekly methotrexate is frequently the recommended first-line therapy for active musculoskeletal disease. Other agents like hydroxychloroquine or newer biologics may be used for refractory cases. The goal of these pharmacological treatments is to suppress the underlying autoimmune activity.
Physical and occupational therapy are the cornerstone of managing stiffness and contractures caused by fibrosis. These non-pharmacological approaches involve consistent stretching and strengthening exercises aimed at maintaining or improving the range of motion in affected joints, especially the hands. Early intervention is crucial to prevent the progression of fibrotic contractures and maintain daily function.