Pediatric Annals

FROM THE GUEST EDITOR 

Hemostatic Disorders in Children

Jeanne M Lustier, MD

Abstract

The five topics covered in this issue of Pediatric Annals encompass hemostatic disorders that are frequently encountered by the pediatrician, yet "problems" exist in their proper diagnosis, management, or both.

Idiopathic thrombocytopenic purpura is one of the most common bleeding disorders in children and is fairly easy to recognize. Buchanan discusses approaches to diagnosis and management for both acute and chronic forms of the disease, including the pros and cons of various therapeutic modalities.

Montgomery and Kroner discuss von Willebrand disease, which is by far the most common of the hereditary disorders of blood coagulation, von Willebrand disease affects at least 1% of the population, is worldwide in distribution, and affects all racial groups, yet its diagnosis remains challenging. In fact, the physician who first examines such a patient may not even think of von Willebrand disease. When it is considered, appropriate diagnostic tests must be obtained and interpreted, which is not always an easy task. In terms of bleeding symptoms, bleeding of the mucous membranes predominates; however, von Willebrand disease is heterogeneous, with a wide spectrum of severity.

As noted by the authors, the underlying defect in von Willebrand disease is in a large multimeric plasma protein called von Willebrand factor. In type 1, the most common form of von Willebrand disease, von Willebrand factor is produced in subnormal amounts, but what is produced is structurally and functionally normal. Bleeding in type 1 can often be treated (or prevented) by the synthetic agent des-amino-D-arginine vasopressin (DDAVP), which effects a transient release of von Willebrand factor from its storage sites in endothelial cells. In the less common type 2 and the severe type 3 variants, the von Willebrand factor produced is structurally and functionally abnormal. For type 2 and type 3 von Willebrand disease, the treatment of choice is a plasmaderived factor VHl concentrate that is rich in the high molecular weight multimers of von Willebrand factor.

Kadir and Lee discuss menorrhagia in adolescent girls. When examining adolescent girls and young women who have excessive menstrual bleeding, pediatricians often think of gynecologic pathology only. However, many (11% to 17%) of these young women actually have von Willebrand disease, chronic (autoimmune) idiopathic thrombocytopenic purpura, or another underlying hematologic disorder. The authors discuss the definition and causes of menorrhagia, the difficulties in obtaining an accurate menstrual history, and the major health implications of menorrhagia in adolescents. They also discuss management and follow-up.

Kulkarni reviews hereditary and acquired bleeding disorders in neonates, emphasizing the need for communication between the obstetrician and the pediatrician and the need for the pediatrician to be knowledgeable about hemostasis in the newborn. She also emphasizes the need to consider the possibility of intracranial hemorrhage, so that the diagnosis can be made quickly and appropriate management instituted.

Warrier discusses a problem that has increased in recent years - thrombotic disorders in infancy and childhood. Many of these disorders are iatrogenic, resulting from the use of central venous lines and potentially thrombogenic fluids, such as those used for total parenteral nutrition. She also discusses antiphospholipid antibodies and reviews inherited disorders of coagulation that predispose to thrombosis.

It is hoped that these articles, all written by highly experienced experts in the field, will be useful to the practicing pediatrician.

CME PRETEST

HOW TO OBTAIN CME CREDITS BY READING THIS ISSUE

Pediatricians can receive Category 1 credits for the Physician's Recognition Award of the American Medical Association by reading the following articles and successfully completing the quiz at the end of the issue. Complete instructions are given on the quiz pages.

The Pretest below has been prepared to assist you in studying…

The five topics covered in this issue of Pediatric Annals encompass hemostatic disorders that are frequently encountered by the pediatrician, yet "problems" exist in their proper diagnosis, management, or both.

Idiopathic thrombocytopenic purpura is one of the most common bleeding disorders in children and is fairly easy to recognize. Buchanan discusses approaches to diagnosis and management for both acute and chronic forms of the disease, including the pros and cons of various therapeutic modalities.

Montgomery and Kroner discuss von Willebrand disease, which is by far the most common of the hereditary disorders of blood coagulation, von Willebrand disease affects at least 1% of the population, is worldwide in distribution, and affects all racial groups, yet its diagnosis remains challenging. In fact, the physician who first examines such a patient may not even think of von Willebrand disease. When it is considered, appropriate diagnostic tests must be obtained and interpreted, which is not always an easy task. In terms of bleeding symptoms, bleeding of the mucous membranes predominates; however, von Willebrand disease is heterogeneous, with a wide spectrum of severity.

As noted by the authors, the underlying defect in von Willebrand disease is in a large multimeric plasma protein called von Willebrand factor. In type 1, the most common form of von Willebrand disease, von Willebrand factor is produced in subnormal amounts, but what is produced is structurally and functionally normal. Bleeding in type 1 can often be treated (or prevented) by the synthetic agent des-amino-D-arginine vasopressin (DDAVP), which effects a transient release of von Willebrand factor from its storage sites in endothelial cells. In the less common type 2 and the severe type 3 variants, the von Willebrand factor produced is structurally and functionally abnormal. For type 2 and type 3 von Willebrand disease, the treatment of choice is a plasmaderived factor VHl concentrate that is rich in the high molecular weight multimers of von Willebrand factor.

Kadir and Lee discuss menorrhagia in adolescent girls. When examining adolescent girls and young women who have excessive menstrual bleeding, pediatricians often think of gynecologic pathology only. However, many (11% to 17%) of these young women actually have von Willebrand disease, chronic (autoimmune) idiopathic thrombocytopenic purpura, or another underlying hematologic disorder. The authors discuss the definition and causes of menorrhagia, the difficulties in obtaining an accurate menstrual history, and the major health implications of menorrhagia in adolescents. They also discuss management and follow-up.

Kulkarni reviews hereditary and acquired bleeding disorders in neonates, emphasizing the need for communication between the obstetrician and the pediatrician and the need for the pediatrician to be knowledgeable about hemostasis in the newborn. She also emphasizes the need to consider the possibility of intracranial hemorrhage, so that the diagnosis can be made quickly and appropriate management instituted.

Warrier discusses a problem that has increased in recent years - thrombotic disorders in infancy and childhood. Many of these disorders are iatrogenic, resulting from the use of central venous lines and potentially thrombogenic fluids, such as those used for total parenteral nutrition. She also discusses antiphospholipid antibodies and reviews inherited disorders of coagulation that predispose to thrombosis.

It is hoped that these articles, all written by highly experienced experts in the field, will be useful to the practicing pediatrician.

CME PRETEST

HOW TO OBTAIN CME CREDITS BY READING THIS ISSUE

Pediatricians can receive Category 1 credits for the Physician's Recognition Award of the American Medical Association by reading the following articles and successfully completing the quiz at the end of the issue. Complete instructions are given on the quiz pages.

The Pretest below has been prepared to assist you in studying the following material. It indicates some of the areas to be covered and will make it possible for you to challenge your present knowledge of the material before reading further.

EDUCATIONAL OBJECTIVES

Although not often faced with true hemophilia, the office pediatrician is many times challenged by the child with frequent epistaxis or the adolescent girl with menorrhagia. How to deal with these patients is something pediatricians are often not well trained to do. Although many pediatricians are aware of how to screen for bleeding disorders by history, many are unprepared for how to adequately and completely evaluate the child with a suspected bleeding diathesis.

This issue of Pediatric Annals provides a review of bleeding disorders in children. Presentation, historical warning signs, laboratory evaluation, and therapy are all extensively discussed. After reading this issue, the participant should be well prepared to face the child with a bleeding disorder in the clinic setting.

PRETEST

1. Although idiopathic thrombocytopenic purpura (ITP) is said to be triggered by a prior viral infection, supportive evidence for this is lacking.

A. True.

B. False.

2. A careful clinical history is the most sensitive method to diagnose von Willebrand disease in children.

A. True.

B. False.

3. Adolescent dysfunctional uterine bleeding is a selflimiting condition, which generally resolves with the maturation of the hypothalamic-pituitary-gonadal axis.

A. True.

B. False.

4. Factors VII, XII, and IX are the only clotting factors that cross the placenta.

A. True.

B. False.

10.3928/0090-4481-20010901-06

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