At SLE diagnosis, pleuritis (19.2% vs. 5.6%; p = 0.035), autoimmune hemolytic anemia (AIHA) (38.5% vs. 18.6%; p = 0.037), and C3 hypocomplementemia (80.8% vs. 55.4%; p = 0.014) were significantly more common in the hemangioma group. Here, C3 is linked to hemangioma.