Diagnosis of Scleroderma
Major and minor criteria for the diagnosis of scleroderma were developed by the American College of Rheumatology. The major criterion is thickening of the skin on arms (usually the fingers and hands) and on the face, neck, chest, or abdomen. Minor criteria include thickening of the skin on the fingers, depressions (called pitting) or tissue loss of the pads of the fingers, and the development of abnormal tissue at the base of both lungs (bibasilar pulmonary fibrosis). A patient is diagnosed with systemic sclerosis when one major and two minor criteria are present.
Diagnosis involves a physical examination, laboratory tests (e.g., blood tests), and imaging tests. Blood tests that may be performed include the following:
- Antinuclear antibody (present in more than 95% of cases)
- Erythrocyte sedimentation rate (ESR; detects inflammation in the body)
- Hypergammaglobulinemia (detects excess gamma globulin [protein antibody])
- Hemolytic anemia (red blood cell deficiency caused by the breakdown of the cells)
Additional blood tests (e.g., creatine phosphokinase, BUN and creatinine) may be performed when muscle or kidney involvement is suspected.
In patients with lung involvement, pulmonary function tests may be performed. Suspected heart involvement may be diagnoses using electrocardiography (ECG) and a Holter (24-hour) monitor.
Imaging tests that may be used include ultrasound and computed tomography (CT scan).