Newman: Thrombocytopenia Flashcards
NL platelet count
150- 450 x103/uL
Thrombocytopenia
< 150 x 103/uL
Problem with primary hemostasis
< 75 x 103/uL
Spontaneous bleeding possible
< 50 x 103
Clinically significant bleeding possible
<20 x 103
Life threatening hemorrhage bleeding possible
<10 x 103
What are purpura?
Purple/red spots on skin that do not blanch on pressure. Caused by bleeding under skin. Bigger than petechiae.
What are the 4 most common conditions associated with fetal/neonatal thrombocytopenia?
- Alloimmune thrombocytopenia
- Congenital infection (CMV, toxoplasma, rubella, HIV)
- Aneuploidy (triomy 18, 13, or 21 or triploidy)
- AI conditions (i.e., ITP, SLE)
HUS presents after _________ with a classic triad of ________
Acute gastroenteritis (within 2 weeks)
1. MAHA
2. Thrombocytopenia
3. Acute renal damage/failure
What are red flags for LOW platelets?
1. Petechiae/purpura
2. Gingival bleeding
3. Epistaxis
4. Menorrhagia
5. GI bleeding
6. Hematuria
7. CNS hemorrhage
8. Eccchymosis/bruises
when should we worry about bruises?
1. Multiple
2. Atypical distribution
3. Bruising inconsistent with activity or force or injury
Which disorder in children causing thrombocytopenia is a primary platelet consumption syndrome?
Idiopathic thrombocytopenia purpura
What is ITP (idiopathic thrombocytopenic purpura)?
What is acute ITP?
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.
How does acute idiopathic thrombocytopenic purpura (ITP) most commonly manifest in a child?
Platelet level/morphology?
- 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
Labs in acute ITP?
- Platelet count = <20,000
- Large platelets
- Other cell lines = NL; if not, do a bone marrow aspirate
- PT/PTT = NL
- Reticulocyte count = NL
- DAT = negative
- Quanatative Ig = NL
Which 3 treatments are MC used for acute ITP (ONLY when severe or life-threatening hemorrhage)?
- IVIG
- - Prednisone (or other corticosteroid)
- Anti-D immunoglobulin (only in Rh (-) children)
What is the goal of treatment of acute ITP?
Keep platelets >20 x 103
Usually supportive! (No ASA, ibuprofin, contact sports, reassurance and education)
Does acute ITP ever progress to chronic ITP?
Becomes chronic in 20% of cases (if lasts 12 months),
In adolescents, 50% become chronic.
After 12 months of ongoing ITP (chronic) in a child, what other disorders should you evaluate for?
- AI diseases (SLE, chronic infections like HIV)
- Non-immune diseases (platelet type vWF, x-linked thrombocytopenia)
- H. pylori infection***
Hemolytic-uremic syndrome (HUS) is due to what?
Vascular injury (especially kidneys and colonic mucosa) from toxins from E.coli O157:H7 => causing consumption of platelets
What is the only cell line involved in ITP?
Platelets
Typical patient with Wiscott-Aldrich Syndrome and findings
Young male with
- 1. Eczema
- 2. Recurrent infections,
- 3. Small platelets
Which 2 disorders causing thrombocytopenia in children are due to combined platelet (thrombocytopenia) and fbrinogen consumption (hypofibringinomia)?
- DIC
- Kasabach-Merritt syndrome
Kasabach-Merrit syndrome can be associated with early-onset neonatal (<72 hrs) thrombocytopenia and what other finding?
Large hemangiomas + intravascular coagulation
