Thrombocytopenia

Question 1

Etiology overview

Answer 1

1. Reduced production
2. Decreased survival
3. Sequestration
4. Dilutional

Question 2

Causes of reduced production

Answer 2

1. Selective impairment->durgs, infectin
2. Nutritional deficiencies
3. Bone marrow failure->aplastic anemia
4. Bone marrow replacement
5. Ineffective hematopoiesis

Question 3

Causes of decreased survival

Answer 3

1. Immunological
SLE, B cell lymphoid, RA, Antiphospholipid
Infection, HIV, CMV
ITP
Drugs
Post transfusion
2. Non-immunological
DIC
Microangiopathies
\++hemangiomas
HELLP

Question 4

History if normal medical history and first time presenting with extremely low PLT count

Answer 4

New medication
Quinine
Infection, HIV?
Pregnancy
FHx
Rheumatological
Malignancy
Surgery/transfusion
Travel, malaria

Question 5

If patient only has bleeding

Answer 5

Immune destruction

Drug/toxin

Question 6

Clouded sensorium, renal anomalies

Answer 6

TTP

DIC

Question 7

Further history

Answer 7

1. Easy bruising, petechiae, epistaxis, gum bleeding, GI/GU
2. Bone pain, night sweats, weight loss, nausea, anorexia, fatigue, weak, LLQ discomfort (splenomegaly)
3. fever, hemoptysis, chills, rigors, rash, laryngitis, DNV
4. Joint, arthraligia, morning stiff, malar, weight loss, cough, dyspnea, hx miscarriage, diarrheal illness (HUS), confusion and neurology (TTP)
5. Surgery, confusion/dys/cough (DIC)
6. Excess alcohol
7. Atopy, hearing loss
8. Symptoms of hypothyroid
9. Fatigue, breathless, chest pain
10. Old PLT counts
11. FHx, diet, travel, illness, vaccinations, ICU, alcohol/drugs
12. Medication history

Question 8

Physical examination

Answer 8

General: petechiae, retinal hemorrhage, bleeding

1. Hepatosplenomegaly/LN+, adenopathy, bone pain/ fracture/weakness (MM), pallor
2. White spots on tongue, jaundice/+liver, retinal changes (CMV)
3. Joint deformity, LN, rash
4. Hypotension/tachy/bleed (DIC), HTN in pregnancy (HELLP), seizures/arrythmia/jaundice (TTP)
5. Bleeding at IV/catheter sites etc
6. Peripheral edema/hair loss/bradyC/hypothyroid
7. Evidence of cirrhosis/portalhypertension

Question 9

Investigations

Answer 9

1. Peripheral smear
2. FBC w/ differential
3. CT head if IC bleed suspected

Results of smear determine further testing
1. Plasma electrophoresis, serum calcium, beta2mucroglobulin, BM aspirate, XR
2. Serum LDH, reticulocyte, indirect bilirubin, PT, PTT, fibrinogen, d dimer, creatinine->TTP
3. If cirrhosis suspected: LFTs, albumin, coags, ANA, ferritin, anti-SM, ceruloplasmin, USS, ammonia etc
4. CT abdomen->cirrhosis, splenomegaly, mets, lymphoma
5. If AI->ANA, RF, anti cardiolipin, lupus anticoagulant, CXR
6. BM if suspect aplastic anemia
7/ B12 and folate
8. Renal function
9. Infection: CMV, EBV, HIV, ,malaria