Newman: Thrombocytopenia

Question 1

NL platelet count

Answer 1

150- 450 x10³/uL

Question 2

Thrombocytopenia

Answer 2

< 150 x 10³/uL

Question 3

Problem with primary hemostasis

Answer 3

< 75 x 10³/uL

Question 4

Spontaneous bleeding possible

Answer 4

< 50 x 10³

Question 5

Clinically significant bleeding possible

Answer 5

<20 x 10³

Question 6

Life threatening hemorrhage bleeding possible

Answer 6

<10 x 10³

Question 7

What are purpura?

Answer 7

Purple/red spots on skin that do not blanch on pressure. Caused by bleeding under skin. Bigger than petechiae.

Question 8

What are the 4 most common conditions associated with fetal/neonatal thrombocytopenia?

Answer 8

1. Alloimmune thrombocytopenia
2. Congenital infection (CMV, toxoplasma, rubella, HIV)
3. Aneuploidy (triomy 18, 13, or 21 or triploidy)
4. AI conditions (i.e., ITP, SLE)

Question 9

HUS presents after _________ with a classic triad of ________

Answer 9

Acute gastroenteritis (within 2 weeks)

1. MAHA

2. Thrombocytopenia

3. Acute renal damage/failure

Question 10

What are red flags for LOW platelets?

Answer 10

1. Petechiae/purpura

2. Gingival bleeding

3. Epistaxis

4. Menorrhagia

5. GI bleeding

6. Hematuria

7. CNS hemorrhage

8. Eccchymosis/bruises

Question 11

when should we worry about bruises?

Answer 11

1. Multiple

2. Atypical distribution

3. Bruising inconsistent with activity or force or injury

Question 12

Which disorder in children causing thrombocytopenia is a primary platelet consumption syndrome?

Answer 12

Idiopathic thrombocytopenia purpura

Question 13

What is ITP (idiopathic thrombocytopenic purpura)?

What is acute ITP?

Answer 13

AI condition where the body makes AB to platelets (thrombocytes => purpura)

• • Spleen makes IgG autoAB to GPIIb/3a-R on platelets => destruction via spleen and liver (short lifespan).

If acute = sudden onset of patechie and bruising, MC in children 1-2 weeks after viral infection. Goes away by itself in a couple of months.

Question 14

How does acute idiopathic thrombocytopenic purpura (ITP) most commonly manifest in a child?

Platelet level/morphology?

Answer 14

- Sudden onset of petechiae and bruising in otherwise well child; 1-2 weeks after a viral infection and goes away by itself in 6 months.

• Platelet count usually <20x103/uL —> platelets look large

Question 15

Labs in acute ITP?

Answer 15

1. Platelet count = <20,000
2. Large platelets
3. Other cell lines = NL; if not, do a bone marrow aspirate
4. PT/PTT = NL
5. Reticulocyte count = NL
6. DAT = negative
7. Quanatative Ig = NL

Question 16

Which 3 treatments are MC used for acute ITP (ONLY when severe or life-threatening hemorrhage)?

Answer 16

1. • IVIG
2. - Prednisone (or other corticosteroid)
3. • Anti-D immunoglobulin (only in Rh (-) children)

Question 17

What is the goal of treatment of acute ITP?

Answer 17

Keep platelets >20 x 10³

Usually supportive! (No ASA, ibuprofin, contact sports, reassurance and education)

Question 18

Does acute ITP ever progress to chronic ITP?

Answer 18

Becomes chronic in 20% of cases (if lasts 12 months),

In adolescents, 50% become chronic.

Question 19

After 12 months of ongoing ITP (chronic) in a child, what other disorders should you evaluate for?

Answer 19

1. AI diseases (SLE, chronic infections like HIV)
2. Non-immune diseases (platelet type vWF, x-linked thrombocytopenia)
3. H. pylori infection***

Question 20

Hemolytic-uremic syndrome (HUS) is due to what?

Answer 20

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

Question 21

What is the only cell line involved in ITP?

Answer 21

Platelets

Question 22

Typical patient with Wiscott-Aldrich Syndrome and findings

Answer 22

Young male with

• 1. Eczema
• 2. Recurrent infections,
• 3. Small platelets

Question 23

Which 2 disorders causing thrombocytopenia in children are due to combined platelet (thrombocytopenia) and fbrinogen consumption (hypofibringinomia)?

Answer 23

1. DIC
2. Kasabach-Merritt syndrome

Question 24

Kasabach-Merrit syndrome can be associated with early-onset neonatal (<72 hrs) thrombocytopenia and what other finding?

Answer 24

Large hemangiomas + intravascular coagulation

Question 25

Late onset neonatal (>72 hr) thrombocytopenia is almost always due to what?

Answer 25

Late-onset sepsis

Question 26

How should you manage and eval a patient that may have platelet disorders?

Answer 26

1. H&P
2. CBC + differential (& peripheral smear)
3. PT/PTT
4. Platelet function analyzer (platelet aggregation testing(
5. BM aspirate, if you see changes in other cell lines.