Haemophilia, Von Willebrand, ITP Flashcards Preview

Paeds - Haematology + Oncology > Haemophilia, Von Willebrand, ITP > Flashcards

Flashcards in Haemophilia, Von Willebrand, ITP Deck (12)
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1
Q

Haemophilia Ex and RF:

A
  • Commonest severe inherited coagulation disorder
  • X-linked recessive
  • Haemophilia A - Factor VIII deficiency, 1 in 5000 male births (MORE COMMON)
  • Haemophilia B (Christmas disease) - Factor IX deficiency 1 in 30000 male births
    RF: Family History, MORE COMMON IN MALES
2
Q

Clinical presentation of Haemophilia?

A

Graded:
Mild - bleed after surgery, Moderate - bleed after minor trauma, Severe - spontaneous bleeding into muscles and joints.
- Severe disease characterised by recurrent spontaneous bleeding into muscles and joints - can lead to crippling arthritis if not treated.
- Majority of children present towards end of the 1st year of life when they start to walk or crawl and fall over -> bleeding episodes.
- Episodes are most frequent into joints and muscles.
- 40% present in neonatal period with inter cranial haemorrhage or prolonged oozing from heel-prick and venipuncture sites.

Ddx: VWD - similar bleeding symptoms to mild haemophilia - tends to be more mucosal bleeding.

3
Q

Diagnosis of Haemophilia?

A

1) Decreased or absent factor VIII or IX

2) Prolonged activated prothomboplastin time (aPTT)

4
Q

Treatment of Haemophilia?

A

1) Recombinant factor VIII concentrate in Haemophilia A or recombinant factor IX concentrate in Haemophilia B via IV infusion whenever there is bleeding.
- Home treatment is encouraged to avoid delay in treatment which increases risk of permanent damage.
- Prophylactic factor VIII given to all children from 2 yrs to reduce risk of chronic joint damage.

2) DESMOPRESSIN (DDAVP) - can be used in mild haemophilia A - stimulates endogenous release of factor VIII and vWF (von Willebrand factor)

5
Q

Complications of treatment?

A

1) Development of antibodies to Factor VIII/IX - reduces or completely inhibits effect of treatment requiring vary high doses of factor VIII for treating bleeding.
2) Transfusion-transmitted infection - Hep A, B, C, HIV.
3) Vascular access - difficult to cannulate peripheral veins, central venous access device may become infected or thrombosed.

6
Q

Von Willebrand Disease Ex and PPx?

A
  • vWF has 2 major roles: facilitate platelet adhesion to damaged endothelium, and it is a carrier protein for Factor VIII protecting it from inactivation and clearance.
  • vWD is autosomal DOMINANT.
  • Results from either quantitative or qualitative deficiency of vWF resulting in:
    1) Defective platelet plug formation
    2) Defective factor VIII
  • DIfferent subtypes based on severity, type 1 usually mild and not diagnosed until puberty/adulthood.
7
Q

Clinical presentation of vWD and DDx?

A

1) Brusing
2) Excessive prolonged bleeding after surgery
3) Mucosal bleeding - epistaxis (nose bleeds)
4) Menorrhagia

Ddx: Haemophilia (more spontaneous soft tissue bleeding resulting in large haematomas.

8
Q

Diagnosis and Tx of vWD?

A

Dx: Prolonged activated prothomboplasyin time (aPTT)

Tx:

1) Desmopressin (DDAVP) - type 1: use cautiously in children under 1 - can cause excess water retention - hyponatraemia - seizures.
2) More severe types require PLASMA DERIVED FACTOR VIII concentrate, must be PLASMA DERIVED as recombinant does not contain vWF.

9
Q

Immune thrombocytopenia (ITP) Ex:

A

ITP - LOW PLATELET COUNT

  • Commonest cause of thrombocytopenia in childhood.
  • Usually caused by destruction of platelets in circulation by anti-platelet IgG autoantibodies.
  • Most children present 2-10yrs with onset often 1-2 weeks after a viral infection.
  • Usually self-limiting course over 1-2 weeks.
  • More acute than adults.
10
Q

ITP presentation?

A

1) Petechiae - small purple/red spots caused by bleeding into skin
2) Purpura - rash of purple spots on the skin caused by internal bleeding from small blood vessels.
3) Superficial brusing
4) Epistaxis (nose bleeds) and other mucosal bleeding but profuse bleeding rare
5) Intercranial bleeding RARE complication

11
Q

ITP Diagnosis?

A

1) Diagnosis of exclusion - care attention to history and clinical features
2) Blood film - to exclude more sinister diagnosis
3) Young children - congenital cause (Wiskott-Aldrich syndrome) should be considered
4) Any atypical features - neutropenia, anaemia, hepatosplenomegaly, lymphadenopathy should prompt bone marrow examination to exclude leukaemia and aplastic anaemia.
5) Bone marrow examination should occur if child TREATED WITH STEROIDS - this can mask acute lymphoblastic leukaemia (ALL)
6) Consider SLE

12
Q

ITP Treatment?

A

IN 80% of cases - acute benign and self-limiting - remitting within 6-8 weeks

  • Most children can be managed at home and do not require hospital admission
  • Treatment required if MAJOR bleeding (inter cranial or GI haemorrhage): Oral prednisolone, IV anti-D, IV IG (controversial due to many side effects).
  • Platelet transfusion only in life threatening haemorrhage - platelet count only increases for few hours.
  • Parents need 24-hr access, avoid contact sports and trauma while low platelet count.

Chronic ITP:
In 20% its platelet count remains low 6 months after diagnosis, treatment mainly supportive.
- Drug treatment only offered to children with chronic persistent bleeding affecting daily activities and quality of life.
- Regular screening for SLE should be performed, as the thrombocytopenia may predate the development of autoantibodies.