Platelet Disorders - lecture

Question 1

Work-up for thrombocytopenia

Answer 1

1. exclude pseudothrombocytopenia on smear

Platelets less than 100,000:
abnl smear or WBC or RBC suggests BM ds
Large spleen - hypersplenism
Immune mediated - primary or secondary ITP, drug induced thrombocytopenia

Platelets greater than 100,000:
Follow CBC - stable, continue to follow CBC, if less than 100,000 review smear as above

Question 2

Work-up for thrombocytosis

Answer 2

If evidence of underlying dz - have reactive thrombocytosis

If no evidence of underlying dz perform JAK2 V617F genotyping

• Wild-type and t(9;22)+ = CML
• Wild-type t(9;22) - and mutant –> marrow histology = reactive thrombocytosis or differentiate ET from CMPD or MDS

Question 3

Thrombocytopenia - general

Answer 3

most common cause of bleeding - risk inversely proportional to platelet count

Petechiae common

Purpura - larger bleed, confluent petechiae
-also seen in coagulopathies, connective tissue dz (palpable purport in leukocytoclastic vasculitis)

Question 4

Thrombocytosis - general

Answer 4

usually asymptomatic

with essential thrombocythemia (a myeloproliferative disorder) may have bleeding, thrombosis, or both as a component of their presentation

Question 5

Erythromelalgia

Answer 5

Vasomotor changes that occur in patients with essential thrombocythemia

Burning pain may accompany

Good responses to baby ASA daily