Generalized purpura with thrombocytopenia

Probable diagnosis

History and examination

Symptoms and signs of thrombocytopenic purpura

• Pinpoint, non-blanching petechiae, often initially on dependent areas such as the legs
• Generalized purpura and easy bruising/ecchymoses
• Epistaxis, gingival bleeding
• Oral blood blisters or “wet purpura”
• Menorrhagia or prolonged bleeding after minor trauma
• Hematuria, melena, hematemesis in severe disease
• Headache, vomiting, altered consciousness, or focal neurology may indicate intracranial bleeding

Look specifically for

Evaluation

1. Establish urgency

• Active major bleeding or hemodynamic instability
• Suspected intracranial bleed or new neurologic symptoms
• Platelet count usually <10 × 10⁹/L, particularly with bleeding
• Severe mucosal bleeding or wet purpura
• Anemia with schistocytes, renal dysfunction, fever, or neurologic change
• Suspected TTP, DIC, acute leukemia, or sepsis

2. Core investigations

1. Repeat CBC with platelet count
   • Confirm the result and assess anemia/leukopenia.
2. Peripheral blood smear
   • Platelet clumps: pseudothrombocytopenia
   • Schistocytes: TTP/HUS/DIC or another microangiopathic hemolytic anemia
   • Blasts: acute leukemia
   • Giant platelets: possible inherited thrombocytopenia or peripheral platelet destruction
3. Coagulation screen: PT/INR, aPTT, fibrinogen, D-dimer
   • Abnormal coagulation tests and low fibrinogen suggest DIC rather than ITP.
4. Hemolysis screen: reticulocyte count, LDH, indirect bilirubin, haptoglobin, direct antiglobulin test
5. Renal and liver function tests, urinalysis
6. Pregnancy test in people who could be pregnant
7. HIV and hepatitis C testing in suspected ITP; consider hepatitis B before immunosuppressive therapy
8. Targeted investigations based on context:
   • ANA/dsDNA and complement if SLE is suspected
   • Malaria testing where relevant
   • Blood cultures and infection evaluation if febrile
   • ADAMTS13 activity/inhibitor sample if TTP is suspected, but do not delay treatment
   • HIT evaluation using a 4Ts assessment and PF4 testing if compatible heparin exposure

3. Bone marrow examination

• Age over 60 years
• Other cell lines are abnormal
• Blasts/dysplasia or atypical cells on smear
• Hepatosplenomegaly/lymphadenopathy
• No response to initial ITP treatment or diagnosis remains unclear

Key differential diagnoses

1. Immune thrombocytopenia

• Isolated thrombocytopenia
• Normal coagulation profile
• No schistocytes or systemic illness
• Petechiae, bruising, mucosal bleeding
• Primary or secondary to HIV, hepatitis C, SLE, etc.

2. TTP: do not miss

3. DIC

• Often sepsis, trauma, obstetric catastrophe, malignancy
• Thrombocytopenia plus prolonged PT/aPTT, high D-dimer, falling fibrinogen, and schistocytes

4. Drug-induced thrombocytopenia

5. Bone-marrow disorders

• Acute leukemia
• Aplastic anemia
• Myelodysplastic syndrome
• Marrow infiltration
• Usually associated with anemia and/or leukopenia, abnormal smear, constitutional symptoms, or organomegaly.

Management

General measures

• Admit if significant bleeding, very low platelet count, diagnostic uncertainty, or concern for TTP/DIC/sepsis.
• Avoid IM injections, rectal procedures, contact sports, aspirin, NSAIDs, and unnecessary antiplatelet/anticoagulant drugs.
• Treat any underlying trigger: infection, secondary autoimmune disease, liver disease, or drug exposure.
• Use local measures and antifibrinolytic treatment when appropriate for mucosal bleeding, under clinician supervision.

If likely ITP without major bleeding

• Observation may be appropriate for no/minor bleeding and a safe platelet count.
• Short-course corticosteroids are conventional first-line therapy for patients needing treatment.
  • Prednisone or high-dose dexamethasone are commonly used.
  • Avoid prolonged corticosteroid courses if possible because of toxicity.
• IVIG is useful where a rapid platelet rise is needed, such as clinically important bleeding, very low count, or urgent procedure.
• Anti-D immunoglobulin may be an option in selected Rh-positive, non-splenectomized patients.
• For persistent/chronic disease, hematology-directed options include:
  • Thrombopoietin receptor agonists: eltrombopag, romiplostim, avatrombopag
  • Rituximab
  • Fostamatinib in selected refractory cases
  • Splenectomy, generally deferred until persistent disease and after appropriate vaccination/counseling

If major or critical bleeding in ITP

• IV corticosteroids
• IVIG
• Platelet transfusion for life-threatening or significant active bleeding, generally alongside IVIG and steroids because transfused platelets are otherwise rapidly destroyed
• Site-specific management, for example neuroimaging and neurosurgical input if intracranial hemorrhage is possible

If TTP is suspected

• Draw ADAMTS13 samples if feasible, but start treatment immediately
• Urgent daily therapeutic plasma exchange with plasma replacement
• Corticosteroids
• Specialist-directed caplacizumab and immunosuppression such as rituximab when appropriate
• Do not rely on platelet transfusion unless bleeding is life-threatening, because it can worsen thrombosis

If DIC or sepsis is suspected

• Treat the underlying cause urgently, especially sepsis or obstetric/traumatic triggers.
• Use blood products based on bleeding, procedures, and coagulation results, not platelet count alone.

Bottom line