Immune Thrombocytopenic Purpura Flashcards
Define Immune Thrombocytopaenic Purpura (ITP)?
Syndrome characterised by immune destruction of platelets resulting in bruising or a bleeding tendency
What is the aetiology of ITP?
Often IDIOPATHIC
Acute ITP is often seen after viral infection in children
Chronic ITP is more common in adults
Autoantibodies are generated, which bind to platelet membrane proteins (e.g. GlpIIb/IIIa) resulting in thrombocytopaenia
What is ITP associated with?
Infections (e.g. malaria, EBV, HIV)
Autoimmune disease (e.g. SLE, thyroid disease)
Malignancies
Drugs (e.g. quinine)
What is the epidemiology of ITP?
Acute ITP presents in children aged 2-7
Chronic ITP is seen in ADULTS
4x more common in women
What are the presenting symptoms of ITP?
Easy bruising
Mucosal bleeding
Menorrhagia
Epistaxis
What are the signs of ITP on physical examination?
Visible Petechiae and bruises
Signs of other illness (e.g. infections, wasting, splenomegaly) would suggest that other causes
What investigations do we do for ITP?
Diagnosis of exclusion
Bloods
Blood Film
Bone Marrow
What diagnoses do we exclude for ITP?
Myelodysplasia
Acute leukaemia
Marrow infiltration
What bloods do we do for ITP?
FBC
Clotting Screen
Autoantibodies (e.g. antiplatelet antibody)
What do we see on a FBC for ITP?
Low Platelets
What do we see on a Clotting Screen for ITP?
Normal PT, APTT and fibrinogen
Why do we do a Blood Film for ITP?
To rule out pseudothrombocytopaenia (which is caused by platelets clumping together and giving falsely low counts)
Why do we Bone Marrow tests for ITP?
To exclude other pathology
