Immune Thrombocytopenic Purpura Flashcards
What is thrombocytopenia?
A platelet count of less than 150x10^9/L.
What dictates the risk of bleeding in thrombocytopenia?
The severity
What is considered to be severe thrombocytopenia?
Platelets <20 x 10^9/L
What risk is severe thrombocytopenia associated with?
Spontaneous bleeding
What is considered to be moderate thrombocytopenia?
Platelets 20-50 x 10^9/L
What risk is moderate thrombocytopenia associated with?
Excess bleeding during operations or trauma
Is there a risk of spontaneous bleeding with moderate thrombocytopenia?
Low risk
What is considered to be mild thrombocytopenia?
50-150 x 10^9/L
What risk is mild thrombocytopenia associated with?
Low risk of bleeding, unless there is a major operation or severe trauma
What is the most common cause of thrombocytopenia in childhood?
Immune thrombocytopenic purpura
What is the incidence of ITP in children?
About 4 in 100,000 / year
What is ITP caused by?
Destruction of circulating platelets by anti-platelet IgG antibodies
What might the reduced platelet count be associated with in ITP?
A compensatory increase in megakaryocytes in the bone marrow
What are the risk factors for ITP?
- Female gender
- Recent viral infections
Give 3 viral infections that ITP may follow?
- Mumps
- Measles
- Respiratory infection
When do most children with ITP present?
Between the ages of 2 years and 10 years
What does the onset of ITP often follow?
1-2 weeks after viral infection
How long is the history of ITP?
In the majority of children, there is a short history of days or weeks
What are the symptoms of ITP?
- Petechiae
- Purpura
- Superficial bruising
- Epistaxis and other mucosal bleeding
What kind of diagnosis is ITP?
Diagnosis of exclusion
What is the importance of ITP being a diagnosis of exclusion?
Careful attention must be paid to history, clinical features, and a blood film to ensure a more sinister diagnosis is not missed
What are the differential diagnoses of ITP?
- Congenital conditions
- Acute leukaemia or aplastic anaemia
- SLE
What congenital conditions are differentials for ITP?
- Wiskott-Aldrich
- Bernard-Soulier syndrome
Why is ITP not always concerning?
In about 80% of children, the disease is acute, benign, and self limiting, usually remitting spontaneously within 6-8 weeks
Where can most children with ITP be managed?
At home, without need for hospital admission
Why is treatment for ITP controversial?
Because most children do not need any therapy, even if the platelet count is less than 10 x 10^9/L
When should treatment for ITP be given?
If there is any evidence of major bleeding
Give two examples of sources of major bleeding in ITP?
- Intracranial
- Gastrointestinal
What are the treatment options for ITP?
- Oral prednisolone
- IV anti-D
- IV immunoglobulins
- Platelet transfusions
What is the problem with treatments for ITP?
All the treatments have serious side effects
What are platelet transfusions used for in ITP?
Reserved for life-threatening haemorrhage
Why are platelet transfusions reserved for life threatening haemorrhage in ITP?
As they only raise platelet count for a few hours
What general measures should be taken when a child with ITP has a very low platelet count?
- Parent needs immediate 24-hour access to hospital
- Child should avoid trauma, e.g. contact sports
What is chronic ITP?
When the platelet count remains low for 3 months after diagnosis
What % of children with ITP will have chronic ITP?
20%
What is the treatment for chronic ITP in the majority of children?
Mainly supportive
When is drug treatment offered to children with chronic ITP?
Children with persistent bleeding that affects daily activity or impairs quality of life
Is it common for children with chronic ITP to have significant bleeding?
No, it is rare
What treatments are available for chronic ITP?
- Rituximab
- Thrombopoietic growth factors
- Splenectomy
Give an example of a complication of ITP
Intracranial bleeding
