Thrombocytopenias and Thrombocytosis Flashcards
What is thrombocytopenia?
Low platelets
This is caused by reduced platelet production in the bone marrow, excessive peripheral destruction of platelets or sequestration in an enlarged spleen
What classes can the causes of thrombocytopenia be divided into?
- Impaired production
- Excessive Destruction/increased consumption
- Sequestration
- Dilutional
What are causes of impaired production which leads to thrombocytopenia?
- Selective megakaryoctye depression
- Bone marrow failure
- Myelodysplastic syndromes
- Myeloma
- Myelofibrosis
- Solid tumour infiltration
- Aplastic anaemia
- HIV infection
What are causes of excessive destruction or increased consumption which can lead to thrombocytopenia?
- Autoimmune - ITP
- Drug induced
- Post-tranfusion purpura
- DIC
- Thrombotic thrombocytopenia purpura
What are causes of sequestration of platelets leading to thrombocytopenia?
- Splenomegaly/Hypersplenism
What are causes of dilutional thrombocytopenia?
Massive transfusion
If thrombocytopenia was caused by a something which impaired production, how would you treat it?
- Treat the cause
- If platelets are critically low - platelet tranfusion
What is immune thrombocytopenic pupura?
Thrombocytopenia is due to immune destruction of platelets. The antibody-coated platelets are removed following binding to Fc receptors on macrophages.
What age range does ITP present in children?
2-6 years old
What can precipitate the development of ITP in children?
Infection - recent viral infection, including varicella zoster or measles
How soon after infection can ITP present in children?
Approx 2 weeks after infection
What are features of acute ITP?
Common
- Easy bruising
- Purpura
- Epistaxis
- Menorrhagia
Rare
- Major haemorrhage
Does someone with ITP typically present with splenomegaly?
No - extremely rare
Which sex is ITP characteristically seen in adults?
Females
What is the overriding feature of chronic ITP?
Fluctuating course of bleeding, epistaxis etc.