Immune thrombocytopenic purpura (ITP)

A 35-year-old woman presents with easy bruising, epistaxis, and menorrhagia for the past 3 months. Blood tests show:

• Hb: 12 g/dL
• WBC: 7 × 10⁹/L
• Platelets: 18 × 10⁹/L
• PT: Normal
• APTT: Normal
• Blood film: No abnormal cells

What is the most likely diagnosis?

A) Von Willebrand disease
B) Immune thrombocytopenic purpura (ITP)
C) Disseminated intravascular coagulation (DIC)
D) Thrombotic thrombocytopenic purpura (TTP)
E) Aplastic anaemia

Correct Answer:

B) Immune thrombocytopenic purpura (ITP)

Explanation:

ITP is an autoimmune condition causing isolated thrombocytopenia due to platelet destruction.

• Chronic ITP occurs in adults; acute ITP is more common in children.
• Normal PT and APTT (rules out coagulation disorders).
• No abnormal cells on blood film (rules out malignancy).
• A) Von Willebrand disease → Incorrect. Causes prolonged APTT and mild thrombocytopenia, not severe thrombocytopenia.
• C) DIC → Incorrect. Causes prolonged PT/APTT, low fibrinogen, and is usually associated with sepsis or malignancy.
• D) TTP → Incorrect. Causes thrombocytopenia + haemolytic anaemia + neurological signs.
• E) Aplastic anaemia → Incorrect. Would show pancytopenia (low Hb, WBC, and platelets).

Key Tips for PLAB 1:

✅ Isolated thrombocytopenia + normal coagulation = ITP.
✅ First-line treatment = Corticosteroids (IVIG if severe bleeding).
✅ If refractory, splenectomy or rituximab.