Immune Thrombocytopenia (ITP) Flashcards
1
Q
Define ITP
A
Immune thrombocytopenia (ITP), also known as immune thrombocytopenic purpura, is defined as an autoimmune haematological disorder characterised by isolated thrombocytopenia (<100 × 10⁹/L) in the absence of an identifiable cause.
2
Q
Aetiology of ITP
A
- Primary ITP is due to an autoimmune phenomenon and involves antibody destruction of peripheral platelets.
-
Secondary ITP includes all forms of ITP where associated medical conditions or precipitants can be identified:
- SLE
- HIV
- Hep C
- Lymphoma
- Leukaemia (CLL)
- Medications
3
Q
Risk Factors for ITP
A
- Women of childbearing age
- Age < 10: post-viral infection
- Age > 65: tends to be an incidental finding usually due to a chronic illness
4
Q
Presenting Symptoms of ITP
A
This is a diagnosis of exclusion
- Asymptomatic (an incidental finding)
-
Minor mucocutaneous bleeding (less common)
-
Subcutaneous: bruising, petechiae, purpura
- In Children, there is an abrupt onset of bleeding following viral infection
- Mucosal: gum bleeding
-
Subcutaneous: bruising, petechiae, purpura
- Lack of splenomegaly, hepatomegaly and drugs that cause thrombocytopenia (heparin, alcohol)
5
Q
Physical Examination in ITP
A
- Petechiae mostly on lower limbs - can be found anywhere is thrombocytopenia is severe enough
6
Q
Investigations
A
-
FBC: isolated ↓ platelet count (< 100,000/mm3) and other cell lines normal
- EDTA bottles can falsely lower platelet count
- Peripheral blood smear: normal to large platelets
- Bleeding time: may be prolonged
Additional investigations:
- All adults: HIV and HCV screening
- Bone marrow biopsy
- Findings: normal or ↑ megakaryocytes
- No evidence of malignancy
7
Q
Management
A
Management
first-line treatment for ITP is oral prednisolone
pooled normal human immunoglobulin (IVIG) may also be used
it raises the platelet count quicker than steroids, therefore may be used if active bleeding or an urgent invasive procedure is required
