A 55-year-old woman presents with Raynaud's phenomenon for 5 years, dysphagia after eating for 2 years, generalized swelling sensation, thick and hard skin on both hands, and facial skin without wrinkles. Blood pressure (BP) is 160/94 mmHg for the past week. Urinary protein ++ (1.5g/d), urine sediment shows red blood cells (RBCs) 10-15 per high power field (HPF). Blood urea nitrogen (BUN) 1 mmol/L, serum creatinine (Scr) 240 μmol/L. The primary diagnostic criterion for systemic sclerosis in this case is: