What is the recommended diagnostic work‑up and management for a newly diagnosed patient with idiopathic thrombocytopenic purpura presenting with isolated thrombocytopenia and a platelet count below 30 × 10⁹/L or mucocutaneous bleeding?

Management of Idiopathic Thrombocytopenic Purpura with Platelets <30 × 10⁹/L

For newly diagnosed ITP patients with platelet counts below 30 × 10⁹/L or mucocutaneous bleeding, initiate corticosteroids (prednisone 0.5-2 mg/kg/day or dexamethasone 40 mg/day for 4 days) as first-line treatment, with IVIg (0.8-1 g/kg) reserved for patients requiring rapid platelet response or those with significant mucosal bleeding. 1, 2

Diagnostic Work-Up

Essential Initial Testing

The diagnosis of ITP is primarily clinical, based on history, physical examination, complete blood count, and peripheral blood smear examination to exclude other causes of thrombocytopenia. 1, 3

• Confirm true thrombocytopenia by repeating platelet count using heparin or sodium citrate tube to exclude EDTA-induced pseudothrombocytopenia, which occurs in approximately 0.1% of adults 4, 3

• Review peripheral blood smear directly to confirm actual thrombocytopenia, assess platelet morphology, and look for platelet clumping or abnormal cell lines that suggest alternative diagnoses 1, 3

• Obtain HIV antibody testing in patients with risk factors, as HIV commonly causes thrombocytopenia 1, 4

• Perform hepatitis C testing in appropriate patients 3

• Assess for splenomegaly via physical examination; if suspected, obtain abdominal CT scan or ultrasound, as splenomegaly argues strongly against ITP 1, 4

Testing NOT Routinely Indicated

• Bone marrow aspiration should NOT be performed before initiating treatment in newly diagnosed patients with typical presentation 1, 3

• Bone marrow examination is reserved for patients with persistent thrombocytopenia lasting >6-12 months, those unresponsive to IVIg, or when history/physical/smear suggest alternative diagnoses 1, 3

• Platelet antibody testing is NOT recommended due to lack of sensitivity and specificity 3

Risk Stratification and Hospitalization Criteria

Adults Requiring Admission

• Platelet count <20 × 10⁹/L with asymptomatic or minor mucocutaneous bleeding 4, 3

• Significant mucosal bleeding (wet purpura, epistaxis, oral bleeding) regardless of platelet count 4, 2

• Patients on anticoagulant or antiplatelet medications with increased bleeding risk 4

• Elderly patients (>60 years) who have higher bleeding risk 1, 4

• Social concerns, diagnostic uncertainty, or significant comorbidities with bleeding risk 4

Children Requiring Admission

• Severe, life-threatening bleeding regardless of platelet count 1, 4

• Platelet count <20 × 10⁹/L with mucous membrane bleeding that may require intervention 1, 4

Treatment Algorithm

For Platelet Count <30 × 10⁹/L WITHOUT Bleeding or Minor Bleeding Only

Observation is preferred over immediate corticosteroid treatment for patients with platelet counts 20-30 × 10⁹/L and no bleeding or only minor skin manifestations 2

Corticosteroids are recommended over observation for patients with platelet counts <30 × 10⁹/L who have any of the following: 1, 2

• Quality of life significantly diminished by disease burden
• Upcoming procedures or surgery
• Profession/lifestyle predisposing to trauma
• Need for anticoagulation therapy

For Platelet Count <30 × 10⁹/L WITH Mucosal Bleeding

First-Line Treatment Options:

• Prednisone 0.5-2 mg/kg/day (maximum 120 mg daily) until platelet count increases to 30-50 × 10⁹/L, which may require several days to weeks; rapidly taper and stop after 4 weeks in non-responders to avoid corticosteroid complications 1, 2

• Dexamethasone 40 mg/day for 4 days produces 86-90% initial response rate with 50-74% sustained response lasting median 8 months when given as 1-4 cycles every 14-28 days 1, 2

• IVIg 0.8-1 g/kg as single dose is preferred when rapid platelet response is needed (response within several days), particularly for patients requiring urgent procedures or with significant mucosal bleeding 1, 2

• IV anti-D 50-75 μg/kg for Rh-positive, non-splenectomized patients; contraindicated in patients with anemia or active bleeding due to hemolysis risk 1, 2

For Life-Threatening or Severe Bleeding

Emergency treatment requires immediate triple therapy: 1, 2

• High-dose parenteral corticosteroids: methylprednisolone 1 g IV daily or dexamethasone 40 mg IV daily 1, 2

• IVIg 0.8-1 g/kg as single dose 1, 2

• Platelet transfusions at 2-3 fold larger than usual doses 2

• Hospitalize and provide conventional critical care measures for intracranial hemorrhage, severe GI bleeding, or organ-threatening hemorrhage 1, 2

Activity Restrictions Based on Platelet Count

• Platelet count <10 × 10⁹/L: Avoid competitive contact sports and activities with high risk of head trauma 2

• Platelet count 10-30 × 10⁹/L: Limit high-risk activities or initiate treatment 2

• Platelet count >30 × 10⁹/L: No activity restrictions required 2

Follow-Up Requirements

• All outpatients require hematology follow-up within 24-72 hours of diagnosis 4, 2

• Provide patient education about warning signs requiring emergency care: significant bleeding, high fever, rapid fall in platelet count 4

• Discontinue NSAIDs and antiplatelet agents in all ITP patients 2

• Menstruating patients may require tranexamic acid or hormonal contraceptives to suppress menses 2

Critical Pitfalls to Avoid

• Do NOT treat based solely on platelet count—bleeding symptoms and clinical context are paramount for treatment decisions 4, 2

• Do NOT use prolonged corticosteroid courses (>6 weeks)—rapidly taper prednisone after 4 weeks in non-responders to avoid serious complications 1, 2

• Do NOT use IV anti-D in anemic patients or those with active bleeding—risk of exacerbating hemolysis 1, 2

• Do NOT assume ITP without excluding secondary causes—HIV, hepatitis C, medications, and antiphospholipid syndrome must be ruled out 4, 3

• Do NOT perform routine bone marrow biopsy—only indicated when history, physical, or smear suggest alternative diagnoses 1, 3

• Do NOT delay hematology referral—patients with newly diagnosed ITP and platelet count <30 × 10⁹/L require specialist evaluation within 24-72 hours 4, 2