Thrombocytopenia - Immune Thrombocytopenic Purpura (ITP)

Question 1

Definition

Answer 1

Low platelet count due to autoimmune destruction of platelets (not production) + purpuric non-blanching rash
Primary = often post viral infection, self limiting
Secondary = malignancies, HIV

Question 2

Types of ITP

Answer 2

T1= Mainly seen in children below 10 post viral infection, acute and severe
T2 = adult women with malignancy, HIV, Hep C or other AI conditions, chronic and mild

Question 3

Epidemiology

Answer 3

Acute - < 10 or > 65
Chronic - Women of child bearing age

Question 4

Pathophysiology

Answer 4

Type 2 hypersensitivity reaction, IgG mediated which targets GPIIb/IIIa + target platelets for destruction in the spleen
- antibodies form against platelets
- spontaneous
- secondary to trigger e.g. viral infection

Question 5

Aetiology

Answer 5

Primary ITP: when it occurs itself
Secondary ITP: triggered by another condition
- Hep C
- HIV
- Lupus

Question 6

Signs and symptoms

Answer 6

Present within 24-48 hours
(can be asymptomatic)
- bleeding = gums, nose (epistaxis), periods
- bruising
- petechiae (pin prick spots 1mm) or purpura (3-10mm)
Major haemorrhages, splenomegaly rare

Question 7

Investigations

Answer 7

FIRST LINE = FBC
- Isolated thrombocytopenia
- Normal leukocyte
- Normal RBC.
Blood film - megakaryocytes start releasing large platelets = mean platelet volume increase
Rule out heparin induced thrombocytopenia + leukaemia

Question 8

Treatment

Answer 8

Primary ITP:
- non severe: monitor + spontaneous remission within 3 months
- severe: active bleeding + severe thrombocytopenia (below 30k)
First line = Prednisolone or IV immunoglobulins
Second line = splenectomy
Third line (below 10k) = blood transfusions = platelets transfusions - only work temporarily because the antibodies against platelets will begin destroying the transfused platelets as soon as they are infused
Secondary ITP treat underlying cause

Question 9

Educational advice to give for people with ITP

Answer 9

Avoid contact sport
Avoid intramuscular injections and procedures such as lumbar punctures
Avoid NSAIDS, aspirin, and blood thinning medications
Advice on managing nosebleeds
Seek help after any injury that may cause internal bleeding for example car accidents or head injury

Question 10

Complications

Answer 10

Chronic ITP
Anaemia
Intracranial and subarachnoid haemorrhage
GI bleed