Primary Haemostasis Problems Flashcards
How is HHT inherited?
AD
Where are the mutations in HHT?
ENG
ALK1
SMAD4
Describe the pathogenesis of HHT?
Causes dilation of capillaries and small arterioles
How does HHT present?
Small, blanching red spots on nose and throughout GI tract
What condition results from HHT?
Iron def anaemia
due to recurrent GI bleeds and epistaxis
How does easy bruising syndrome present?
Bruises (funnily enough) on arms, legs, trunk
What causes senile purpura?
Atrophy of collage in endothelial wall
What other conditions have the same pathogenesis as senile purpura?
Scurvy
Steroid induced bruising
What kind of reaction is HSP?
Type III hypersensitivity
What does HSP commonly follow?
URTI
How does HSP present?
Mostly purpura on legs and butt Abdo pain Haematuria Glomerulonephritis Arthritis
How is HSP treated?
Usually not and patients make spontaneous recovery
What is ITP?
Immune mediate destruction of platelets
Which age group is most commonly affected by ITP?
Kids 2-6
How does ITP present?
Epistaxis Purpura Menorrhagia Easy bruising Commonly follows viral illness in kids
Which antibodies are associated with ITP in adults?
Antibodies against glycoprotein IIb/IIIa or Ib
Compare onset of ITP in kids vs adults
Kids - acute
Adults - chronic, less severe
What does bone marrow aspirate show in ITP?
Normal or increased megakaryocytes
What does FBC show in ITP?
Thrombocytopenia
How is ITP managed?
Not usually as spontaneous recovery common
How is ITP with severe bleeding managed in kids?
Corticosteroids
IV Igs
Anti-D
How is ITP with severe bleeding treated in adults?
Prednisolone 1mg/kg/day
IV Igs
Platelet transfusions
Describe TTP
vWF is not cleaved properly so its big
More platelets then stick to it, form clots and block small vessels (thrombosis)
This uses up all the platelets in the body so there is a tendency to bleed (thrombocytopenia)
How does TTP present?
Purpura
Fever
Haemolytic anaemia
Fluctuating cerebral dysfunction
Give secondary causes of TTP
OCP SLE infection pregnancy clopidogrel treatment
In which group is TTP more common?
Overweight, black women
What is von Willebrand’s disease?
vWF def causing defective platelet function and factor VIII def
How is VW disease inherited?
AD - type 1 and 2
AR - type 3
Where is the mutation in VW disease?
vWF gene of chromosome 12
Describe type 1 VW disease
Quantitative
Describe type 2 VW disease
Qualitative
How does VW disease present?
Epistaxis
Bruising
Bleeding after minor trauma
What do investigations show in VW disease?
PT normal
APTT prolonged
Decreased vWF
Factor VIII:C ratio reduced
How is VW disease treated?
Factor VIII replacement therapy if mod-sev disease
