Stiff hands and feet, facial deformities
The appearance of the skin on this woman’s face, hands, and feet helped us to recognize an advanced case of an autoimmune disease.
Lab tests, imaging studies are used to diagnose SSc
Generally, blood testing in patients with SSc may show thrombocytopenia, hypergammaglobulinemia, or (in patients with renal involvement of SSc) elevated blood urea and creatinine levels. Creatine kinase, erythrocyte sedimentation rate, and C-reactive protein may be elevated due to myositis, vasculitis, malignancy, or an overlap of systemic sclerosis with another autoimmune disease.3
Serologic testing. Antinuclear antibodies (ANA) are positive in 60% to 80% of patients with SSc.2 Antibodies to topoisomerase-1 (Scl-70 antibodies) are present in 30% of cases of dSSc.2 The presence of either anticentromere antibodies (ACA) or anti-Scl-70 is highly specific (95%-99%) for the diagnosis of lSSc and dSSc, respectively.2 Anti-polymerase 1 and 3 antibodies (RNAP) are associated with dSSc and a significantly higher incidence of renal involvement.4
Capillary microscopy can be helpful in showing dilated, tortuous, and enlarged capillaries in the nail fold and adjacent areas. It is an effective method for distinguishing between primary and secondary Raynaud’s phenomenon.6
Chest x-ray. The lungs are involved in approximately 80% of all patients with SSc, and lung involvement is the leading cause of morbidity and mortality.7 The 2 most common types of direct pulmonary involvement are interstitial lung disease and pulmonary hypertension, which together account for 60% of SSc-related deaths.8
Key elements of sclerodermal lung disease are inflammation, lung scarring, and pulmonary hypertension due to progressive scarring of the inner lining of the small arteries. Inflammation and scarring of lung tissue causes interstitial lung disease. This is more common in dSSc, whereas pulmonary hypertension is more common in lSSc.8 In ssSSc, pulmonary disease can occur without any skin involvement. High-resolution computer tomography scans of the lungs (HRCT) can sensitively detect scarring and severity of lung inflammation, while a simple chest x-ray cannot.9 Interstitial abnormalities on HRCT have been found in 90% of patients.9
Spirometry. Interstitial lung disease leads to a reduction in forced vital capacity (FVC) and diffusing capacity of the lungs for carbon monoxide (DLCO). Significant pulmonary involvement is detectable in 25% of patients with SSc within 3 years of diagnosis.10 Interstitial fibrosis shows a restrictive pattern on spirometry. Forced expiratory volume in 1 second (FEV1) and FVC are reduced, and the FEV1/FVC ratio is normal or increased.
