A 17-year-old girl comes to the emergency department due to a nosebleed that began an hour ago after she was hit in the face by a basketball. She pinched the nostrils for about 20 minutes in an attempt to stop the bleeding, but the hemorrhage continued after pressure was removed. The patient has a history of heavy, painful menses and takes scheduled ibuprofen for the first few days of her period. Her last period was a week ago. Temperature is 37.2 C (99 F). Examination shows clear lung fields with normal S1 and S2. The liver span measures 8 cm along the midclavicular line, and the spleen is not palpable. Scattered ecchymoses are present on both legs and arms. Laboratory results are as follows: Which of the following is the most likely cause of this patient's condition?

Question

A 17-year-old girl comes to the emergency department due to a nosebleed that began an hour ago after she was hit in the face by a basketball.  She pinched the nostrils for about 20 minutes in an attempt to stop the bleeding, but the hemorrhage continued after pressure was removed.  The patient has a history of heavy, painful menses and takes scheduled ibuprofen for the first few days of her period.  Her last period was a week ago.  Temperature is 37.2 C (99 F).  Examination shows clear lung fields with normal S1 and S2.  The liver span measures 8 cm along the midclavicular line, and the spleen is not palpable.  Scattered ecchymoses are present on both legs and arms.  Laboratory results are as follows:  Which of the following is the most likely cause of this patient's condition?

Quizplus · Accepted Answer

11ec25c8_d5e7_5ffd_bc81_43260d4a97a6_MD0003_00 This patient has bleeding episodes and isolated thrombocytopenia, likely due to immune thrombocytopenia (ITP). ITP is an autoimmune disorder in which IgG autoantibodies against platelet membrane glycoproteins cause increased platelet destruction and inhibition of platelet production. Presentation is most common in healthy children (age 2-5) or adolescents with petechiae, ecchymoses, and mucosal bleeding (eg, epistaxis, heavy menses). Other than bruising, physical examination is generally unremarkable. Patients have a normal liver span (eg, 6-12 cm at midclavicular line) and nonpalpable spleen. Although ITP is a common cause of isolated thrombocytopenia (ie, normal hematocrit and leukocytes), it is a diagnosis of exclusion. Prolonged bleeding warrants workup with coagulation tests (PT, PTT, fibrinogen), which are normal in patients with ITP. Observation alone is sufficient for mild ITP (cutaneous manifestations) in children, whereas glucocorticoids, anti-D immune globulin (if Rh-positive and Coombs-negative), or intravenous immunoglobulin is the treatment for bleeding. Hormonal therapy may also be considered in patients with heavy menses. (Choice A) Nonsteroidal anti-inflammatories (eg, ibuprofen) block production of thromboxane A2, which can impair platelet function but would not result in the severe thrombocytopenia seen in this patient. (Choice B) Malignant infiltration of the bone marrow, as seen in leukemia, typically results in pancytopenia. It is unlikely in this patient with isolated thrombocytopenia and no hepatosplenomegaly. (Choice C) Decreased von Willebrand factor can present in adolescent girls with heavy menstrual bleeding. Although platelet function is affected, platelet count is typically normal. (Choice D) ADAMTS13 is deficient in thrombocytopenic purpura, which is characterized by thrombocytopenia and microangiopathic hemolytic anemia (not seen in this patient). (Choice E) Disseminated intravascular coagulation is associated with hyperactivation of coagulation and fibrinolysis. Patients typically have thrombocytopenia, microangiopathic hemolytic anemia, low levels of clotting factors (fibrinogen, factors V and VIII), and prolonged PT and PTT. Educational objective: Immune thrombocytopenia is an autoimmune disorder with increased platelet destruction and inhibition of platelet production due to IgG autoantibodies against platelet membrane glycoproteins. Patients may have mucocutaneous bleeding with isolated thrombocytopenia and no hepatosplenomegaly. References: Immune thrombocytopenia: pathophysiologic and clinical update. (http://www.ncbi.nlm.nih.gov/pubmed/22753097)

A 17-Year-Old Girl Comes to the Emergency Department Due to a Nosebleed