Which of the following would be the most likely presenting symptom of a patient with Von Willebrand disease during the onset on menstruation?
Correct Answer D:
Von Willebrand's disease is a hereditary deficiency of von Willebrand's factor (VWF), which causes platelet dysfunction. Bleeding tendency is usually mild. Screening tests show a prolonged bleeding time, normal platelet count, and, possibly, a slightly prolonged PTT.
Bleeding manifestations are mild to moderate and include easy bruising; bleeding from small skin cuts that may stop and start over hours; sometimes, increased menstrual bleeding; and abnormal bleeding after surgical procedures (eg, tooth extraction, tonsillectomy).
Diagnosis is based on low levels of VWF antigen and abnormal ristocetin cofactor activity. Treatment involves control of bleeding with replacement therapy (cryoprecipitate or pasteurized intermediate-purity factor VIII concentrate) or desmopressin.
A 4-year-old boy has a history of nosebleeds and easy bruising. There is a similar history among female and male family members. Laboratory investigations show prolonged APTT and normal INR.
Which one of the following is the most likely cause of this boy's symptoms?
Correct Answer D: Von Willebrand's disease (choice D) is a hereditary deficiency of von Willebrand's factor (VWF), which causes platelet dysfunction. Bleeding tendency is usually mild. Screening tests show a prolonged bleeding time, normal platelet count, and, possibly, a slightly prolonged PTT. Diagnosis is based on low levels of VWF antigen and abnormal ristocetin cofactor activity. Treatment involves control of bleeding with replacement therapy (cryoprecipitate or pasteurized intermediate-purity factor VIII concentrate) or desmopressin.
→ Hemophilia A (choice A) and hemophilia B (Christmas disease) (choice B) are X-linked congenital bleeding disorders affecting male infants, usually diagnosed through family history and prolonged PTT. Undiagnosed hemophilia may cause severe bleeding with circumcision. It can also result in significant ecchymosis with minimal trauma or joint and muscle bleeding, usually by the end of infancy or in early childhood. These children have a significantly prolonged PTT and normal PT. Diagnosis is made through measurement of Factor VIII activity for Hemophilia A and Factor IX activity for Hemophilia B.
→ Activated partial thromboplastin time (aPTT) and international normalized ratio (INR) assessments are normal in factor XIII deficiency (choice C). Wiskott-Aldrich syndrome (choice E) is an X-linked recessive disorder, which is characterized by immunodeficiency, severely dysfunctional platelets, and thrombocytopenia with microthrombocytes. INR and PTT are normal.
A child is noted to develop easy bruising and excessive bleeding from small skin cuts. Tests show bleeding time is increased and a deficiency of von Willebrand's factor.
What is the appropriate treatment?
Diagnosis is based on low levels of VWF antigen and abnormal ristocetin cofactor activity. Treatment involves control of bleeding with replacement therapy (cryoprecipitate or pasteurized intermediate-purity factor VIII concentrate) or desmopressin (DDAVP) (choice D).
The most common cause of proteinuria in children is:
Orthostatic proteinuria accounts for up to 60% of all cases of asymptomatic proteinuria reported in children, with an even higher incidence in adolescents.
Which of the following is false about neonatal physiologic jaundice?
Correct Answer B:
Physiologic jaundice is caused by a combination of increased bilirubin production secondary to accelerated destruction of erythrocytes, decreased excretory capacity secondary to low levels of ligand in in hepatocytes, and low activity of the bilirubin conjugating enzyme uridine diphosphoglucuronyl transferase.
Physiological jaundice occurs in approximately 50% of newborns. Its onset is on 2 to 3 days of age, with a peak on day 4 to 5, then improves. It disappears usually without treatment by 1 to 2 weeks of age. It almost never causes kernicterus. Jaundice that is visible during the first 24 hours of life is likely to be nonphysiologic; further evaluation is suggested.
Medications are not usually administered in infants with physiologic neonatal jaundice. However, in certain instances, phenobarbital, an inducer of hepatic bilirubin metabolism, has been used to enhance bilirubin metabolism.
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