📋 MOCK OSCE · FCPS, MCPS, MD PAEDIATRICS ⏱ 10 min · IMMUNE THROMBOCYTOPENIA (ITP)

Immune Thrombocytopenic Purpura (ITP)

Candidate task: perform focused examination on a child with suspected ITP (acute onset petechiae/purpura).
Then discuss differential diagnosis, investigations, management & follow‑up.
Pre‑exam Protocol
⏤ · Wash, Warm, Introduce, Position, Expose, Approach ▾

Standard pre‑examination protocol – must be demonstrated:

🖐 Wash hands with sterilizing solution.
🔥 Warm hands and stethoscope.
👋 Introduce yourself to child & parent.
🧍 Position child: supine, sitting, then left lateral (for spleen palpation).
👕 Exposure — chest, abdomen, limbs; warm environment.
➡️ Approach from the right side.
✔ CPSP marker: Pre‑exam Protocol is observed and scored.
1. Clinical Examination (≈6 min)
02 General Look (Inspection from end of bed) ▾

Key observations:

  • Skin: widespread petechiae, purpura, ecchymoses (non‑palpable).
  • Mucous membranes: oral petechiae, gum bleeding, epistaxis.
  • Colour: pallor (if anaemia from bleeding).
  • Facial features: no dysmorphism.
  • Activity: usually well, playful (acute ITP).
👁 Red flags: acute onset petechiae + purpura + no organomegaly + normal growth → ITP.
03 Systemic Haematological Examination ▾

Focused examination:

  • Skin: petechiae (pinpoint, non‑blanching), purpura, ecchymoses; no palpable purpura (unlike vasculitis).
  • Mucous membranes: oral petechiae, buccal haemorrhages, gingival bleeding.
  • Abdomen: no hepatosplenomegaly (if present → consider other diagnoses).
  • Lymph nodes: no lymphadenopathy (if present → consider malignancy).
  • Joints: no haemarthrosis (unlike hemophilia).
  • Bones: no tenderness (unlike leukaemia).
🔍 Key: isolated thrombocytopenia + petechiae + no organomegaly + well child → ITP.
04 General Physical Exam (Hands → Face → Chest → Limbs) ▾

Systematic examination:

  • Hands: petechiae, ecchymoses; no clubbing.
  • Face: conjunctival pallor, oral petechiae, epistaxis.
  • Chest: normal cardiovascular; no murmur (unless anaemic).
  • Pulses: normal.
  • Blood pressure: usually normal.
  • Abdomen: no organomegaly.
  • Lower limbs: petechiae, purpura (often lower extremities).
📏 Anthropometry: weight, length – plot growth; usually normal.
05 Developmental Assessment & Associated Signs ▾

Assess:

  • Motor milestones: normal.
  • Growth: normal.
  • History: recent viral illness (1‑4 weeks prior) – common in ITP.
  • Drug history: exclude drug‑induced thrombocytopenia (e.g., valproate, sulfonamides).
  • Immunisation: MMR vaccine (rarely associated).
  • Bleeding history: mucosal bleeding (epistaxis, gum, menorrhagia).
🧠 Key: ITP is typically a self‑limited condition in children; chronic ITP ( >12 months) may indicate underlying disease.

📋 Case Presentation – (fill in during exam)

This is a _____-year-old child, referred for _____ (petechiae / bruises / nosebleeds). On examination, the child appears _____ (well / pale), with _____ (generalised petechiae / purpura / oral blood blisters). Abdomen: no hepatosplenomegaly. Lymph nodes: no lymphadenopathy. Cardiovascular: normal. Growth: weight _____ percentile, height _____ percentile. Associated signs: _____ (recent viral illness / mucosal bleeding).

2. Viva Discussion (≈4 min)
06 Viva · Differential, Investigations, Management, Follow‑up ▾
🔹 Differential Diagnosis

• Immune thrombocytopenia (ITP) – acute, self‑limited.
• Acute leukaemia (ALL, AML) – pancytopenia, blasts, organomegaly.
• Aplastic anaemia – pancytopenia, hypocellular marrow.
• Drug‑induced thrombocytopenia (valproate, sulfonamides, heparin).
• Infection‑associated (viral, bacterial, HIV, EBV, CMV).
• Hemolytic‑uraemic syndrome (HUS) – microangiopathic haemolytic anaemia.
• Wiskott‑Aldrich syndrome (X‑linked, small platelets, eczema, immunodeficiency).
• Bernard‑Soulier syndrome (giant platelets, autosomal recessive).
• Systemic lupus erythematosus (SLE) – autoimmune cytopenias.
• Evans syndrome – ITP + autoimmune haemolytic anaemia.
• Thrombotic thrombocytopenic purpura (TTP) – fever, neuro, renal, microangiopathic.

🔹 Investigations – Diagnosis

• Complete blood count: isolated thrombocytopenia (platelet count <20,000/µL in acute ITP).
• Peripheral smear: large platelets (megathrombocytes), no blasts; normal WBC/RBC morphology.
• Bone marrow aspirate: not routinely indicated (unless atypical features).
• Coombs test: if anaemia present (to rule out Evans syndrome).
• HIV / EBV / CMV serology: if clinically indicated.

🔹 Investigations – Aetiology

• History of viral infection: 50‑65% cases have preceding viral illness.
• Drug history: recent medications.
• Family history: autoimmune disorders, inherited thrombocytopenia.
• Antinuclear antibody (ANA): if chronic ITP or suspicion of SLE.

🔹 Investigations – Exclude Others

• CBC + smear: to exclude leukaemia (blasts) or aplastic anaemia (pancytopenia).
• Bone marrow: if atypical (organomegaly, pancytopenia, blasts, bone pain).
• Coagulation profile: if bleeding out of proportion to platelet count.
• Renal function / urine: if HUS suspected.

🔹 Investigations – Rule Out Complications

• Clinical monitoring: for severe bleeding (intracranial haemorrhage – rare).
• Serial platelet counts: to monitor response to therapy / spontaneous recovery.
• Coombs test (if anaemia): to monitor for Evans syndrome.

🔹 Management – Across Organ Systems

Observation (Mild ITP)

No treatment; avoid contact sports; parental education; platelet count monitoring.

Intravenous Immunoglobulin (IVIG)

0.8‑1 g/kg (single dose) – rapid rise in platelets (within 24‑48 hours).

Corticosteroids

Prednisone 1‑4 mg/kg/day (short course) – for moderate/severe bleeding.

Anti‑D (RhoGAM)

For Rh‑positive, non‑splenectomized patients; 50‑75 µg/kg IV.

Platelet Transfusion

Only for life‑threatening bleeding (intracranial); transient effect.

Rituximab

For chronic ITP; anti‑CD20 monoclonal antibody; 375 mg/m² weekly x4.

TPO‑R Agonists

Eltrombopag (oral) / Romiplostim (SC) – for chronic ITP (≥6 months).

Splenectomy

Reserved for severe, refractory chronic ITP ( >1 year, ≥4‑5 years old).

Immunosuppressives

Azathioprine, cyclosporine, mycophenolate – for refractory cases.

Psychosocial

Parental education, activity modification, school support.

📈 Prognosis

  • Acute ITP: 70‑80% spontaneous recovery within 6 months.
  • Chronic ITP: ~20% persist >12 months; more common in older children (adolescents).
  • Severe bleeding: <1% (intracranial haemorrhage – rare).
  • Treatment: does not alter long‑term outcome; may reduce bleeding risk.
  • Chronic ITP: may be associated with SLE, Evans syndrome, ALPS, CVID.

📋 Follow‑up Schedule

  • Weekly: platelet counts (until recovery or treatment response).
  • Monthly: for chronic ITP (stable counts).
  • Every 3‑6 months: review bleeding symptoms, medication side effects.
  • Annual: if chronic, screen for SLE, Evans syndrome (Coombs, ANA).
  • Lifelong: if splenectomized – pneumococcal, meningococcal, Hib vaccines; penicillin prophylaxis.
💡 Examiner expectation: systematic differential (ITP vs leukaemia vs aplastic anaemia), appropriate investigations (CBC, smear, bone marrow when indicated), and management (observation, IVIG, steroids, TPO agonists). Know the natural history (spontaneous recovery) and the indications for splenectomy.
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Mock OSCE · Immune Thrombocytopenia (ITP) · Based on Wyne‑Harris, Nelson & Paediatric Haematology