| Associated disorder (underlying disease) |
No |
Yes |
| Age at onset |
Adolescence, young adulthood |
Childhood, old age |
| Pattern of clinical manifestation |
Seasonally variable severity; typical three color change |
Variable; often tends towards permanent acral ischemia |
| Arterial stenosis/ occlusion |
No |
Frequent |
| Digital ulcers |
No |
Frequent |
| Nailfold capillaroscopy |
Normal findings or nonspecific morphological changes |
Depending on underlying disease, nonspecific morphological changes or typical disease pattern (e.g., scleroderma pattern) |
| Autoantibodies |
Negative or low-titer without detection of specific antigens (nonspecific antibodies) |
Positive, with antigen detection (specific antibodies) |
