A 35–year–old man presented with 6 h of epistaxis. He had a lifelong history of von Willebrand disease (vWD) type IIB, but denied previous hospitalizations or transfusions. He reported prior epistaxis episodes that all resolved with pressure, but this bleed did not respond to his usual maneuvers. He denied nasal trauma or nonsteroidal use. He denied headache, dyspnea, easy bruising, bleeding or joint swelling. He had been seen at an outside hospital where he had been given a balloon–inflated posterior nasal–packing device (RhinoRocket) and desmopressin prior to being transferred to our facility. His vital signs were normal. He had periorbital ecchymoses secondary to the RhinoRocket placement, crusted blood around his nares, and a clear nasopharynx with no active bleeding. He had no bruises, no gross blood on rectal exam, and no stigmata of liver disease. His initial liver function and coagulation studies were normal. His platelet count was 74,000 cells/mm3, which was a sharp decline from the count of 137,000 earlier that day. His RhinoRocket was kept in place, and he was started on amoxicillin; an order was given to stop the desmopressin. During his hospital course he remained hemodynamically stable. He recieved oxymetazoline for analgesia, amoxicillin for infection prophylaxis, and 4,300 units of factor VIII, with resolution of his epistaxis and removal of his nasal–packing prior to discharge. His platelet level trended upwards with no requirement for transfusion.
VWD is an inherited disorder caused by deficiency or dysfunction of the glycoprotein von Willebrand factor (vWF). Ordinarily, this protein promotes clotting, by acting both as a platelet binding factor and as a carrier protein for factor VIII. There are various types of the disease, and treatment varies based on the different pathophysiology. These differences have important therapeutic implications, as demonstrated by this case.
Von Willebrand disease type I is the most common, and represents a partial quantitative deficiency in vWF. Desmopressin is useful in this type because it promotes release of vWF and factor VIII from the endothelium. In type III where vWF is almost undetectable, desmopressin has little utility. The type II subtypes represent qualitative problems with vWF. Type IIB, representing 5% of cases, is due to an abnormality in the vWF protein that causes it to bind to platelets; the result is consumptive platelet loss. The initiation of desmopressin for our patient with Type IIB was an error, as it increased levels of vWF, initiating a desmopressin–mediated sequestration of platelets resulting in thrombocytopenia, and potentially inducing a vascular thrombosis. The effect of desmopressin on platelets is transient, so our patient was able to recover once this drug was held. This case underscores the need for clinicians to understand the pathophysiology and classification of vWD to ensure proper management of patients that present with acute bleeds.