From the Guidelines
The diagnostic workup for Systemic Sclerosis (SSc) should begin with a thorough history and physical examination, focusing on skin thickening, Raynaud's phenomenon, and systemic symptoms, and should include specific autoantibody testing, pulmonary function tests, echocardiography, and gastrointestinal involvement assessment, as outlined in the most recent guidelines 1. The initial evaluation should include a complete blood count, comprehensive metabolic panel, erythrocyte sedimentation rate, C-reactive protein, and urinalysis. Specific autoantibody testing is essential, including antinuclear antibody (ANA), anti-Scl-70 (for diffuse cutaneous scleroderma), anticentromere antibody (for limited cutaneous scleroderma), and RNA polymerase III antibody (associated with renal crisis) 1.
Key Components of the Diagnostic Workup
- Pulmonary function tests with diffusion capacity and high-resolution chest CT are crucial to assess for interstitial lung disease, which affects up to 80% of patients 1
- Echocardiography should be performed to evaluate for pulmonary hypertension, particularly in patients with longer disease duration, older age, and/or low diffusing capacity 1
- Gastrointestinal involvement should be assessed with esophageal manometry or barium swallow studies, and screening for malabsorption and nutritional deficiencies should be considered in patients with severe gastrointestinal involvement 1
- Nailfold capillaroscopy can reveal characteristic capillary abnormalities, and a skin biopsy may be helpful in uncertain cases 1
- Renal function should be monitored regularly with blood pressure measurements and urinalysis to detect early signs of scleroderma renal crisis, particularly in patients with early diffuse cutaneous systemic sclerosis (dcSSc) and those positive for anti-RNAPIII antibody 1
Additional Considerations
- Patients with SSc should be screened for other organ involvement, including cardiac involvement, premature atherosclerosis, osteoporosis, and depression, as these conditions are common in patients with SSc and can significantly impact quality of life 1
- Malignancy screening should be performed as per local guidelines, particularly in patients with rapidly progressive dcSSc, weight loss, and elderly patients, as well as those with a history of cyclophosphamide use or autologous haematopoietic stem cell transplantation (AHSCT) 1
- The European Alliance of Associations for Rheumatology (EULAR) recommendations for the pharmacological management of SSc should be consulted for guidance on treatment options, including non-pharmacological and pharmacological interventions 1
From the Research
Diagnostic Workup for Systemic Sclerosis (SSc)
The diagnostic workup for Systemic Sclerosis (SSc) involves a combination of clinical evaluation, laboratory tests, and imaging studies. The goals of the initial history and physical and laboratory examinations are to classify the type of scleroderma as limited cutaneous SSc (lcSSc) or diffuse cutaneous SSc (dcSSc), to estimate disease duration, and to define the extent and severity of organ involvement 2.
Clinical Evaluation
The clinical evaluation of SSc patients includes assessing the extent of skin involvement, presence of Raynaud's phenomenon, digital ulcers, esophageal dysfunction, and other internal organ involvement 2. A points system has been established to evaluate patients with early scleroderma and those with scleroderma spectrum disorders (SSD), which includes factors such as extent of skin sclerosis, pulmonary changes, antinuclear antibodies, pattern of Raynaud's phenomenon, and nailfold bleeding 3.
Laboratory Tests
Laboratory tests for SSc include:
- Antinuclear antibodies (ANA) testing, which can help diagnose SSc and distinguish it from other connective tissue diseases 4
- Anti-Scl-70 antibodies testing, which is specific for SSc and can help diagnose the disease 4
- Complete blood count (CBC), blood chemistry tests, and urinalysis to assess internal organ involvement 2
Imaging Studies
Imaging studies for SSc include:
- Chest X-ray and high-resolution computed tomography (HRCT) to assess pulmonary involvement 2
- Echocardiogram to assess cardiac involvement 2
- Gastrointestinal imaging studies to assess esophageal dysfunction and gut involvement 2
Autoantibody Testing
Autoantibody testing can help characterize the clinical phenotype of SSc patients and predict the risk of major organ involvement. For example, Scl-70 patients show the greatest risk of major organ involvement, followed by ANA+ patients and ACA+ patients 5. The risk of interstitial lung disease (ILD) is higher in Scl-70 patients, and these patients should be monitored closely, irrespective of skin involvement 5.
Classification of SSc
SSc can be classified into two major clinical subsets: limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc) 6, 2. The classification of SSc is based on the extent of skin involvement and the presence of internal organ involvement. Patients with lcSSc have skin thickening below the elbows or knees, while patients with dcSSc have skin thickening above the elbows and knees or on the trunk 2.