Haemophilia and ITP

Question 1

What is haemophilia and how common is it?

Answer 1

Bleeding disorder usually inherited with an X-linked recessive inheritance pattern, resulting from the deficiency of a coagulation factor

o Haemophilia A: deficiency of clotting factor VIII
▪ 1 in 5000 male births

o Haemophilia B: deficiency of clotting factor IX
▪ 1 in 30,000 male births

Question 2

What are the clinical features of haemophilia?

Answer 2

• Most present in first year of life when they start to walk, and fall over
o Bleeding into joints and muscles

▪ Note: DDx = non-accidental injury

• 40% of cases present in neonatal period with intracranial haemorrhage, bleeding postcircumcision or prolonged bleeding from heel prick and venepuncture sites
• Severe disease involves recurrent spontaneous bleeding into joints and muscles
• Can lead to arthritis if not treated

Question 3

What investigations would you do for haemophilia?

Answer 3

APTT: usually prolonged
o Mixing study will show APTT corrected (suggesting clotting factor deficiency)
• Factor VIII and IX assay
• FBC usually normal
• PT normal

Question 4

How do you initially treat bleeding in haemophilia?

Answer 4

• Recombinant factor 8 concentrate for haemophilia A
• Recombinant factor 9 concentrate for haemophilia B

• Acute bleeds are treated with factor concentrates and
anti-fibrinolytics (e.g. amniocaproic acid, tranexamic
acid)

o NOTE: these should be given by prompt IV
infusion whenever there is any bleeding

Question 5

What management may be required longer term for haemophilia?

Answer 5

Analgesia and physiotherapy may be required for
deep bleeds into muscles and joints

Orthopaedic and pain team review may also be
necessary

Desmopressin (DDAVP) may be useful in mild haemophilia A as it stimulates
the endogenous release of factor 8 and vWF

Question 6

What must be avoided in patients with haemophilia?

Answer 6

o IM injections
o Aspirin
o NSAIDs

Question 7

What may be given prophylactically to Haemophilia A patients?

Answer 7

Prophylactic factor 8 is given to all children with severe haemophilia A to further reduce the risk of chronic joint damage

Question 8

Which infections are transfusion transmitted?

Answer 8

Hep A B C
HIV
Prions

Question 9

What is immune thrombocytopenic purpura (ITP)?

Answer 9

Autoimmune haematological disorder characterised by isolated thrombocytopenia in the
absence of an identifiable cause

Most common cause of thrombocytopenia in children (4 per 100,000 per year)

Question 10

What is the pathophysiology of ITP?

Answer 10

o Usually caused by destruction of circulating platelets by antiplatelet IgG
autoantibodies
o Antibodies are directed against the glycoprotein IIb/IIIa or Ib-V-IX complex
o This reduces platelet count
o May be accompanied by compensatory increase of megakaryocytes in the bone
marrow

Question 11

What are the clinical features of ITP?

Answer 11

Most children present between 2-10 years
• Onset tends to be 1-2 weeks after a viral infection (may also occur after a vaccination)
• Typically more acute presentation than in adults
• Children develop petechiae, purpura and/or superficial bleeding
• May have epistaxis and mucosal bleeding
• Intracranial bleeding is a rare but serious complication

Question 12

What investigations do you do for ITP?

Answer 12

Diagnosis of exclusion
• In younger children, a congenital cause (e.g. Wiskott-Aldrich syndrome or Bernard-Soulier
syndrome) should be considered
• Keep an eye out for atypical clinical findings such as:
o Anaemia
o Neutropaenia
o Hepatosplenomegaly
o Marked lymphadenopathy
o NOTE: in the case of abnormal clinical findings, bone marrow examination should be
conducted to exclude acute leukaemia or aplastic anaemia
• NOTE: bone marrow examination is required before treatment with steroids because the
steroid treatment could temporarily mask the diagnosis of acute lymphoblastic leukaemia
(ALL)

Question 13

What is the management of the 20% of ITP cases which are not self limiting?

Answer 13

• Most children can be managed at home → conservative management with repeat FBC in 5-7
days
• Treatment is indicated if there is evidence of major bleeding (e.g. intracranial or
gastrointestinal) or persistent minor bleeding that affects daily life (e.g. excessive epistaxis)
• Life- or Organ-threatening bleeding
o IVIG + corticosteroid + platelet transfusion
o Antifibrinolytics may be used

Question 14

How do you manage a newly diagnosed child?

Answer 14

o Asymptomatic or Minor Bleeding
▪ Observation (most will achieve a normal platelet count eventually)
▪ Most manifestations are limited to the skin
o Major Bleeding
▪ Corticosteroids
▪ IVIG OR anti-D immunoglobulin

Question 15

How do you manage chronic ITP?

Answer 15

o Mycophenolate mofetil
o Rituximab
o Eltrombopag (thrombopoietin agonist)
o 2nd line: splenectomy
o Screen for SLE