Idiopathic Thrombocytopenic Purpura (ITP) with Flare-Up

Definition and Pathogenesis

• Bailey and Love's Short Practice of Surgery 28e, p. 1248
• Current Surgical Therapy 14e, p. 695

Clinical Types

Clinical Features

• Petechiae and ecchymoses (skin + mucous membranes)
• Spontaneous mucosal bleeding: epistaxis, menorrhagia
• Positive tourniquet test
• Spleen NOT palpable in >90% of patients (splenomegaly should raise suspicion for an alternative diagnosis)
• Intracranial hemorrhage - uncommon but the most frequent cause of death

• 50,000/mm³ - mild bleeding only

• <30,000/mm³ - treatment initiation threshold
• <10,000/mm³ - highest risk for major internal bleeding

Investigations

• Platelet count reduced (usually <60 x 10⁹/L); rest of CBC normal
• Peripheral smear - reduced but morphologically normal platelets; no schistocytes (helps distinguish from TTP)
• Coagulation studies - normal (PT, aPTT normal)
• Bone marrow aspiration - plentiful megakaryocytes (rules out aplasia/infiltration)
• Antiplatelet antibody assays and bone marrow biopsy are not part of routine diagnostic workup
• Exclude secondary causes: ANA (SLE), HIV, hepatitis C, antiphospholipid antibodies

Treatment - Step-by-Step

Treatment Decision Threshold

The goal is a safe platelet count (typically ≥30 x 10⁹/L) to prevent major bleeding - not necessarily a normal count.

• Washington Manual of Medical Therapeutics

First-Line Therapy

• Prednisone 1 mg/kg/day with prolonged taper, OR
• Dexamethasone 40 mg orally for 4 days (repeat cycle in non-responders)
• Longer courses are preferred over shorter ones
• Most patients respond within 1-3 weeks
• Limitation: 70-90% of patients relapse when steroids are stopped; steroid therapy should not be prolonged indefinitely

• Dose: 1 g/kg as a single dose (may repeat)
• Used for rapid platelet elevation (e.g., pre-operatively, severe bleeding, pediatric emergencies)
• Does not produce sustained remission

• Effective only in Rh-positive, non-splenectomized patients
• Black box warning: risk of severe hemolysis - requires post-infusion monitoring
• Rarely used now given better alternatives

Second-Line Therapy (Relapsed / Corticosteroid-Refractory ITP)

• Removes the primary site of both antiplatelet antibody production and platelet destruction
• Produces durable complete response in ~65-75% of patients; 15% have partial improvement
• Indicated when:
  • Failure of medical management (including prolonged steroid use with undesired effects)
  • Relapse after treatment with platelet count remaining <30,000/mm³
  • Rare life-threatening acute bleeding unresponsive to medical therapy
• Laparoscopic splenectomy is the preferred approach
• Must identify and remove splenunculi (accessory spleens) - their enlargement causes recurrence
• Prior steroid response predicts a good response to splenectomy
• Administer pneumococcal, meningococcal, and Haemophilus influenzae type B vaccines before (preferred) or after splenectomy

Splenectomy in children remains controversial as >70% achieve complete remission regardless of therapy.

• ~25% achieve remission (platelet >100 x 10⁹/L) at 12 months
• Up to 40% complete response; up to 60% some treatment effect
• Not currently FDA-approved specifically for ITP

• Romiplostim (subcutaneous, weekly)
• Eltrombopag (oral, once daily)
• Avatrombopag (oral, once daily)
• Produce durable platelet count improvement in >90% of ITP patients beginning 5-7 days after initiation
• Potential complication: thromboembolic events

Third-Line / Rescue Therapy (Failing First and Second Line)

• Combination of first- and second-line agents
• Fostamatinib (Syk tyrosine kinase inhibitor) - reduces platelet phagocytosis by macrophages; 18% achieve stable platelet count >50 x 10⁹/L; approved for relapsed/refractory ITP
• Danazol (androgen therapy)
• Immunosuppressants: azathioprine, cyclophosphamide, mycophenolate
• Combination chemotherapy in rare refractory cases

Acute Hemorrhage / Life-Threatening Flare

1. Platelet transfusion + corticosteroids + IVIG simultaneously
2. Platelet transfusions are only temporarily effective (hours) given ongoing platelet destruction; repeated transfusions may be needed while pharmacologic therapy takes effect
3. Tranexamic acid can be used as an adjunct in life-threatening situations

• Mulholland and Greenfield's Surgery 7e, p. 3822

Management Summary (Schwartz's Principles)

Key Points for Flare-Up

• 30-40% of ITP patients develop relapsed/refractory disease after initial therapy
• A flare after corticosteroid taper should prompt escalation to second-line therapy (TPO-RA or splenectomy)
• Good response to steroids at initial diagnosis is predictive of good response to splenectomy
• Secondary causes (SLE, viral infections, medications) must always be reassessed at each flare
• Management of secondary ITP flare requires treating the underlying disease in addition to the ITP-specific therapies above

Recent evidence note (2025): A systematic review and meta-analysis on dapsone in adult ITP was published in Eur J Med Res (Dec 2025, PMID: 41382219), supporting dapsone as a salvage option in relapsed/refractory cases. This is not yet reflected in most major surgical textbooks.