F2 and anemia (phenotype): On examination, a 5 cm necrotic lesion with surrounding warmth and tenderness was observed. Laboratory tests revealed leukocytosis (27,800/μL; reference interval 3,300-8,600/μL), anemia (hemoglobin 6.8 g/dL; reference interval 13.7-16.8 g/dL), elevated C-reactive protein (15.49 mg/dL; reference interval <0.14 mg/dL), and impaired coagulation (prothrombin activity, 64.1%; reference interval 80-120%).