Immune Thrombocytopenic Purpura

Question 1

What is immune thrombocytopenic purpura?

Answer 1

A clinical syndrome where a decreased number of circulating platelets manifests as a bleeding tendency, causing petechiae, ecchymoses, purpura and bleeding from venepuncture sites, nose etc in an otherwise healthy patient.

Question 2

What are ecchymoses?

Answer 2

A flat, blue or purple patch measuring 1cm or more in diameter.

Question 3

What are petechiae?

Answer 3

Small red or purple spots caused by haemorrhage of the capillaries.

Question 4

What are the 2 types of ITP?

Answer 4

May occur in isolation (primary ITP)

May occur in association with other disorders (secondary ITP)

Question 5

What are causes of secondary ITP?

Answer 5

• Other autoimmune disorders (including antiphospholipid antibody syndrome and SLE)
• Viral infections (including CMV, varicella zoster hep C and HIV).
• Infection with H.pylori
• Medications
• Lymphoproliferative disorders

Question 6

Pathophysiology of ITP?

Answer 6

Caused by a type II hypersensitivity reaction:

• Caused by the production of antibodies that target and destroy platelets.
• Can occur spontaneously, or can be triggered by something such as a viral infection.

Question 7

Clinical features of ITP?

Answer 7

Usually present in children under 10 years old.

Often there is a history of a recent viral illness.

The onset of symptoms occurs over 24-48 hours:
* Bleeding, for example from gums, epistaxis or menorrhagia.
* Bruising
* Petechial or purpuric rash, caused by bleeding under the skin.

Question 8

Blood test investigations for ITP?

Answer 8

FBC: isolated thrombocytopenia

Blood film

Question 9

Is bone marrow examination required for ITP?

Answer 9

Only required if the case appears atypical.

Question 10

Management of ITP?

Answer 10

Usually no treatment is required and patients are monitored until platelets return to normal.

Around 70% of patients will remit spontaneously within 3 months

Treatment may be required if patient is actively bleeding or has severe thrombocytopenia (platelets below 10):
* Prednisolone
* IV immunoglobulins
* Blood transfusions if required
* Platelet transfusions only work temporarily

Question 11

What is first line treatment for ITP?

Answer 11

Corticosteroids is first line management for ITP.

This increases platelet production and decreases platelet destruction.

ITP = characterised by low platelet counts and bleeding symptoms.