A 22-year-old woman comes to the emergency department due to continuous gum bleeding after a mouth injury a few hours ago. She was playing doubles tennis and was accidentally struck on her bottom lip by her partner's racquet. The patient has a history of bruising with minor trauma and of heavy menstruation with crampy pain. She has no other medical conditions and takes no medications other than occasional ibuprofen. The patient does not use tobacco, alcohol, or illicit drugs; she eats a balanced diet. Her mother also had a history of "bleeding issues." Blood pressure is 120/70 mm Hg and pulse is 80/min. Oropharyngeal examination shows blood oozing from a gum abrasion. A fading ecchymosis is present on the right calf, but there are no other skin abnormalities. The remainder of the physical examination is normal. Laboratory results are as follows: Which of the following is the most likely cause of this patient's bleeding problem?

Question

A 22-year-old woman comes to the emergency department due to continuous gum bleeding after a mouth injury a few hours ago.  She was playing doubles tennis and was accidentally struck on her bottom lip by her partner's racquet.  The patient has a history of bruising with minor trauma and of heavy menstruation with crampy pain.  She has no other medical conditions and takes no medications other than occasional ibuprofen.  The patient does not use tobacco, alcohol, or illicit drugs; she eats a balanced diet.  Her mother also had a history of "bleeding issues."  Blood pressure is 120/70 mm Hg and pulse is 80/min.  Oropharyngeal examination shows blood oozing from a gum abrasion.  A fading ecchymosis is present on the right calf, but there are no other skin abnormalities.  The remainder of the physical examination is normal.  Laboratory results are as follows:  Which of the following is the most likely cause of this patient's bleeding problem?

Quizplus · Accepted Answer

11ec25c8_d43a_2581_bc81_c9857c963f9d_MD0003_00 Von Willebrand disease (vWD) is the most common inherited bleeding disorder and is typically transmitted in an autosomal dominant fashion. Therefore, a family history of prolonged bleeding is an important diagnostic clue. Most patients are asymptomatic, but a minority (~1%) have easy bruising, skin bleeding, and mucosal bleeding (eg, menstruation), which can occasionally result in iron deficiency (microcytic anemia) due to chronic blood loss. VWD is associated with impaired quantity/activity of von Willebrand factor (vWF), a glycoprotein produced by endothelial cells and platelets. VWF contributes to hemostasis by: Binding platelets to subendothelial components at the site of vascular injury and aggregating platelets to each other, leading to the formation of a platelet plug. Therefore, patients with vWD have impaired platelet-endothelial binding and platelet aggregation, which prolongs bleeding times.Acting as a carrier protein for factor VIII, which is part of the intrinsic (contact activation) coagulation cascade and contributes to fibrin clot formation. Because factor VIII degrades rapidly when not bound to vWF, patients with vWD generally have low factor VIII levels, which may prolong activated PTT. In contrast, PT is normal because the extrinsic coagulation pathway is unaffected. Binding platelets to subendothelial components at the site of vascular injury and aggregating platelets to each other, leading to the formation of a platelet plug. Therefore, patients with vWD have impaired platelet-endothelial binding and platelet aggregation, which prolongs bleeding times. Binding platelets to subendothelial components at the site of vascular injury and aggregating platelets to each other, leading to the formation of a platelet plug. Therefore, patients with vWD have impaired platelet-endothelial binding and platelet aggregation, which prolongs bleeding times. Acting as a carrier protein for factor VIII, which is part of the intrinsic (contact activation) coagulation cascade and contributes to fibrin clot formation. Because factor VIII degrades rapidly when not bound to vWF, patients with vWD generally have low factor VIII levels, which may prolong activated PTT. In contrast, PT is normal because the extrinsic coagulation pathway is unaffected. Acting as a carrier protein for factor VIII, which is part of the intrinsic (contact activation) coagulation cascade and contributes to fibrin clot formation. Because factor VIII degrades rapidly when not bound to vWF, patients with vWD generally have low factor VIII levels, which may prolong activated PTT. In contrast, PT is normal because the extrinsic coagulation pathway is unaffected. intrinsic (contact activation) coagulation cascade (Choice A) Disseminated intravascular coagulation is marked by abnormal activation of coagulation and fibrinolysis, leading to thrombocytopenia and prolonged PT/PTT. It is triggered primarily by malignancy, infection, trauma, or obstetric complication. (Choice B) Hemophilia A, an X-linked recessive disorder that dramatically reduces factor VIII production, usually causes severe bleeding episodes (eg, soft tissue bleeding, hemarthrosis). VWD does not reduce factor VIII production (it increases factor VIII destruction). (Choice C) Factor VIII inhibitors are antibodies that prevent factor VIII function; they usually form due to medications, autoimmune disease, malignancy, or pregnancy (postpartum period). Factor VIII inhibitors are much less common than vWD and are not generally associated with a family history of bleeding. (Choice D) Immune thrombocytopenia is associated with the autoimmune-mediated platelet destruction, leading to easy bleeding, petechiae, purpura, or epistaxis; laboratory examination reveals thrombocytopenia and normal PT/PTT. (Choice F) Vitamin K is a coenzyme necessary for the carboxylation of factors II, VII, IX, and X. Vitamin K deficiency/antagonists (eg, warfarin) prolong INR/PT, leading to increased bleeding risk. This patient's INR and PT are normal. Educational objective: Von Willebrand disease is a genetic disorder associated with impaired activity/quantity of von Willebrand factor, leading to poor platelet-endothelial binding and reduced factor VIII levels. Patients are usually asymptomatic but may have prolonged mucocutaneous bleeding, easy bruising, and prolonged PTT. References: Diagnostic approach to von Willebrand disease. (http://www.ncbi.nlm.nih.gov/pubmed/25712990)

A 22-Year-Old Woman Comes to the Emergency Department Due to Continuous