Ped Thrombocytopenia

Question 1

what platelet level can lead to:

1) impaired primary hemostasis
2) spontaneous bleeding
3) clinically significant bleeding
4) life threatening hemorrhage

Answer 1

1) impaired primary hemostasis: <75,000
2) spontaneous bleeding: <50,000
3) clinically significant bleeding: <20,000
4) life threatening hemorrhage: <10,000

Question 2

most common causes of fetal and neonatal thrombocytopenia

Answer 2

alloimmune thrombocytopenia

congenital infection

aneuploidy (trisomy 18,13)

autoimmune (ITP)

wiskott-aldrich

Question 3

most common causes of early onset neonatal thrombocytopenia (<72 hours)

Answer 3

kasabach meritt

congenital/inherited

congenital infection

autoimmune (ITP)

Question 4

most common causes of late onset neonatal thrombocytopenia (>72 hours)

Answer 4

congenital infection

autoimmune

kasabach-meritt

Question 5

what are the ddx for decreased platelet production

Answer 5

• nutritional deficiencies (B12, folate, iron)
• bone marrow failure or infiltration (aplastic anemia, leukemia, lymphoma)
• genetic (wiscott-aldrich, fanconi, scwachman-diamond, TAR)

Question 6

what are the ddx for increased platelet destruction/consumption

Answer 6

ITP, HUS, TTP, kasabach-meritt

Question 7

what are the ddx for sequestration of platelets

Answer 7

hypersplenism, vWF dz

Question 8

triad of sx for HUS

Answer 8

1) microangiopathic hemolytic anemia
2) thrombocytopenia
3) acute renal damage/failure

Question 9

what are some “red flags” for peds pts leading to investigation for thrombocytopenia

Answer 9

• petechiae
• purpura
• gingival bleeding
• epistaxis
• menorrhagia
• GI bleed
• hematuria
• CNS hemorrhage
• ecchymosis/bruises

Question 10

what is the criteria for diagnosing ITP

Answer 10

• sudden onset of petechiae and bruising (mucosal hemorrhage in 30%)
• 50% cases follow viral infection by 1-3 weeks
• platelet count <20,000 and other cells lines normal
• normal PT/PTT

Question 11

treatment for ITP

Answer 11

goal is to keep platelets above 20,000

• supportive for most pts

severe or life threatening hemorrhage: prednisone, splenectomy

Question 12

diagnostic criteria for CHRONIC ITP

what must you do when it becomes chronic

Answer 12

> 12 months

evaluate for other autoimmune disorders

Question 13

etiology of HUS

Answer 13

vascular injury (especially kidneys and colonic mucosa) from toxins from E. coli O157:H7 causing consumption of platelets

Question 14

what is kasabach-meritt syndrome

Answer 14

thrombocytopenia and hypofibrinogenemia secondary to giant hemangiomas and associated intravascular congestion

Question 15

pathophysiology of henoch-schonlein purpura

Answer 15

IgA vasculitis –> inflammation and bleeding in the small blood vessels

Question 16

clinical presentation of HSP

Answer 16

palpable purpuric rash that develops on lower extremities and buttocks

• joint pain
• abd pain
• bloody urine

Question 17

how to differentiate henoch-schonlein purpura from ITP

Answer 17

HSP has normal platelets