A case of fulminant type 1 diabetes and protein C deficiency complicated by deep vein thrombosis

A 25‐year‐old man was diagnosed with diabetic ketoacidosis (DKA) at the onset of fulminant type 1 diabetes. After acute‐phase DKA treatment including placement of a central venous catheter, a massive deep vein thrombosis (DVT) and pulmonary embolism (PE) were detected on hospital day 15. His protein C (PC) activity and antigen levels were low even 33 days after completing the DKA treatment, indicating partial type I PC deficiency. Severe PC dysfunction, due to overlapping of partial PC deficiency and hyperglycemia‐induced PC suppression, concomitant with dehydration and catheter treatment, may have induced the massive DVT with PE. This case suggests that anti‐coagulation therapy should be combined with acute‐phase DKA treatment in patients with PC deficiency, even those who have been asymptomatic. As patients with partial PC deficiency should perhaps be included among those with severe DVT complications of DKA, venous thrombosis should always be considered as a potential complication of DKA.