Pediatric Thrombocytopenia Flashcards
A normal platelet count is 150,000-450,000/microliter while thrombocytopenia is defined as <150,000/microliter.
At what platelet count do you start to see clinically significant bleeding?
<20,000/microliter
[primary hemostasis is impaired at <75,000, spontaneous bleeding is possible at <50,000, clinically significant bleeding at <20,000, and life threatening hemorrhage possible at <10,000]
Four general categories of thrombocytopenia etiology
Decreased production of platelets (congenital or acquired)
Sequestration of platelets
Increased platelet destruction
Platelet loss or dilution
Which of the following most accurately categorizes idiopathic thrombocytopenia purpura?
A. Primary platelet consumption syndrome
B. Immunologic platelet destruction
C. Non-immunologic platelet destruction
D. Combined platelet and fibrinogen syndrome
E. Neonatal-specific destructive thrombocytopenia
A. Primary platelet consumption syndrome
Which of the following most accurately categorizes maternal HELLP syndrome?
A. Primary platelet consumption syndrome
B. Immunologic platelet destruction
C. Non-immunologic platelet destruction
D. Combined platelet and fibrinogen syndrome
E. Neonatal-specific destructive thrombocytopenia
E. Neonatal-specific destructive thrombocytopenia
Which of the following most accurately categorizes TTP?
A. Primary platelet consumption syndrome
B. Immunologic platelet destruction
C. Non-immunologic platelet destruction
D. Combined platelet and fibrinogen syndrome
E. Neonatal-specific destructive thrombocytopenia
C. Non-immunologic platelet destruction
Which of the following most accurately categorizes DIC and Kassabach-Merritt syndrome?
A. Primary platelet consumption syndrome
B. Immunologic platelet destruction
C. Non-immunologic platelet destruction
D. Combined platelet and fibrinogen syndrome
E. Neonatal-specific destructive thrombocytopenia
D. Combined platelet and fibrinogen syndrome
Which of the following most accurately categorizes HUS?
A. Primary platelet consumption syndrome
B. Immunologic platelet destruction
C. Non-immunologic platelet destruction
D. Combined platelet and fibrinogen syndrome
E. Neonatal-specific destructive thrombocytopenia
B. Immunologic platelet destruction
In terms of impaired or ineffective production of platelets, which of the following most accurately categorizes marrow infiltrative processes and nutritional deficiency states (iron, folate, vitamin B12)?
A. Congenital or hereditary disorder B. Primary hematologic process C. Acquired disorder D. Metaboic inborn errors E. None of the above
C. Acquired disorder
In terms of impaired or ineffective production of platelets, which of the following most accurately categorizes TAR syndrome and Fanconi aplastic anemia?
A. Congenital or hereditary disorder B. Primary hematologic process C. Acquired disorder D. Metaboic inborn errors E. None of the above
A. Congenital or hereditary disorders
In terms of impaired or ineffective production of platelets, which of the following most accurately categorizes wiskott aldrich syndrome?
A. Congenital or hereditary disorder B. Primary hematologic process C. Acquired disorder D. Metaboic inborn errors E. None of the above
B. Primary hematologic process
The four categories of thrombocytopenia etiology include decreased platelet production, increased platelet destruction/consumption, sequestration of platelets, and dilution of platelets. What disorders fit into the category of decreased platelet production?
Nutritional deficiencies (B12, folate, iron)
Bone marrow failure or infiltration (aplastic anemia, leukemia, lymphoma)
Genetic disorders (Wiscott-Aldrich syndrome, Fanconi anemia, Schwachman-Diamond syndrome, Thrombocytopenia-absent radius syndrome)
The four categories of thrombocytopenia etiology include decreased platelet production, increased platelet destruction/consumption, sequestration of platelets, and dilution of platelets. What disorders fit into the category of increased platelet destruction/consumption?
ITP
HUS
TTP
Kassabach Merritt phenomenon
The four categories of thrombocytopenia etiology include decreased platelet production, increased platelet destruction/consumption, sequestration of platelets, and dilution of platelets. What disorders fit into the category of sequestration of platelets?
Hypersplenism
Von Willebrand disease
Clinical manifestations of platelet disorders
Petechiae Purpura Gingival bleeding Epistaxis Menorrhagia GI bleeding Hematuria CNS hemorrhage Ecchymosis/bruises
Young male with eczema and recurrent infection and small platelets — top of Ddx?
Wiscott Aldrich syndrome
Most common cause of isolated thrombocytopenia in otherwise well children, usually preceded by a viral infection by 1-3 weeks
Acute idiopathic thrombocytopenic purpura (acute ITP)
Diagnostic criteria for ITP including platelet count and appearance, other cell lines affected, PT/PTT, platelet function
Platelet count usually <20,000 x 10^9/L (platelets that are present are large)
Other cell lines normal
PT/PTT normal
Platelet function normal
Acute ITP turns into chronic ITP if it lasts more than _______. Chronic ITP is associated with ______ infection
12 months; H.pylori
Thrombocytopenia and hypofibrogenemia secondary to giant hemangiomas and associated intravascular coagulation
Kasabach merritt syndrome
Vascular injury (especially kidneys and colonic mucosa) from toxins from E.coli O157:H7 causing consumption of platelets
Hemolytic uremic syndrome (HUS)
Red flags in a child with thrombocytopenia
Leukopenia or leukocytosis
Anemia
Peripheral blood smear abnormalities (other than low platelets)
Systemic symptoms of illness
Lymphadenopathy/splenomegaly
Causes of HUS in children
Most common in pediatrics is shiga-like toxin from E.coli O157:H7. The associated thrombocytopenia is destructive in nature and is d/t a microangiopathic process causing platelet activation and consumption.
There are causes of primary HUS (i.e., complement-mediated) and other causes of secondary HUS (i.e, related to pneumococcal infection) but they are far less common
