Idiopathic thrombocytopenic purpura (ITP), currently referred to as immune thrombocytopenia, is an acquired autoimmune hematological disorder characterized by isolated thrombocytopenia (platelet count <100,000/µL) in the absence of other identifiable causes of thrombocytopenia.

ITP results from immune-mediated destruction of platelets and, in some cases, impaired platelet production due to autoantibodies targeting platelet surface antigens. The diagnosis is primarily one of exclusion, requiring the elimination of secondary causes such as systemic lupus erythematosus (SLE), HIV infection, hepatitis C, drug-induced thrombocytopenia, lymphoproliferative disorders, and bone marrow failure syndromes.

ITP may present as:

• Acute ITP – more common in children and often self-limiting

• Chronic ITP – more common in adults and lasting >12 months

Epidemiology and Risk Factors

Although the precise etiology remains unclear, several risk factors and associations have been identified:

• Female sex (especially in younger adults)

• Autoimmune disorders (e.g., SLE)

• Viral infections (HIV, HCV)

• Recent vaccination (rare association)

• Certain medications

• Lymphoproliferative disorders

In adults, ITP is more common among young women, while in older populations, the sex distribution tends to equalize.

Clinical Features

Common Signs and Symptoms

Most adult patients present with manifestations of mucocutaneous bleeding due to reduced platelet count. These include:

• Purpura and petechiae

• Easy bruising

• Epistaxis

• Gingival bleeding

• Menorrhagia

• Prolonged bleeding after minor trauma

Severe complications:

• Intracerebral hemorrhage (rare but the most serious and potentially fatal complication)

• Overt life-threatening bleeding is uncommon unless platelet count falls below 10,000/µL

Important Clinical Note:A palpable spleen strongly suggests an alternative diagnosis, as splenomegaly is not typical in primary ITP.

Diagnostic Criteria

ITP is a diagnosis of exclusion. The following criteria are generally applied:

1. Isolated thrombocytopenia (platelet count <100,000/µL)

2. Normal red blood cell and white blood cell morphology

3. Absence of splenomegaly

4. No evidence of secondary causes

Investigations

Laboratory Tests

• Complete blood count (CBC): isolated thrombocytopenia

• Peripheral blood smear: confirms thrombocytopenia and excludes platelet clumping or abnormal cells

• Coagulation profile: usually normal

• HIV and Hepatitis C screening

• Autoimmune screening (if clinically indicated)

Bone marrow examination is generally not required unless:

• Patient is >60 years

• Atypical features are present

• There is lack of response to treatment

Management

Management depends on platelet count, bleeding severity, and patient-specific factors.

Non-Pharmacological Management

SplenectomyIndicated in patients who are refractory to corticosteroid therapy or who relapse after initial response. Splenectomy reduces platelet destruction by removing the primary site of antibody-mediated platelet clearance.

Pharmacological Management

First-Line Therapy

Prednisolone

• Dose: 1 mg/kg/day orally

• Duration: 3–6 months

• Gradual tapering: reduce by 10 mg weekly

• Indicated for platelet counts <30,000–50,000/µL

OR

Intravenous Immunoglobulin (IVIG)

• Dose: 0.4–1.0 g/kg as a single infusion

• Used when rapid platelet increase is required

• May be followed by platelet transfusion in severe bleeding

Alternative short-course steroid regimen:

• 1 mg/kg/day for 7 days

• Taper over one week

Platelet transfusion is reserved for life-threatening bleeding.

Prevention and Monitoring

• Regular platelet monitoring

• Avoidance of antiplatelet drugs (e.g., aspirin, NSAIDs)

• Vaccination prior to splenectomy (pneumococcal, meningococcal, Hib)

• Patient education on bleeding precautions

Complications

• Life-threatening bleeding (e.g., intracranial hemorrhage)

• Adverse effects of long-term corticosteroids

• Postsplenectomy infections (overwhelming post-splenectomy infection syndrome)

• Thromboembolic risk changes secondary to therapy

Prognosis

• Children: often self-limiting

• Adults: frequently chronic and relapsing

• Mortality is low but increases with severe hemorrhagic complications