itp

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by a low platelet count and an increased risk of bleeding. It results from immune-mediated platelet destruction and often reduced platelet production in the bone marrow. It was formerly known as idiopathic thrombocytopenic purpura.

Most cases are primary, with no associated condition; secondary ITP occurs with infections, autoimmune diseases, or certain medications. The pathophysiology involves autoantibodies against platelet surface proteins, leading to splenic destruction, and impaired megakaryopoiesis; T-cell–mediated effects may contribute.

Symptoms range from none to mucocutaneous bleeding. Common signs include petechiae, easy bruising, epistaxis, gum bleeding, and menorrhagia. Diagnosis is by exclusion: isolated thrombocytopenia with otherwise normal blood counts and no obvious secondary cause. Peripheral smear typically shows low platelets with normal or enlarged platelets; bone marrow biopsy is usually reserved for atypical cases or older patients.

Treatment depends on bleeding risk, platelet count, and patient factors. Mild disease may be observed without therapy. First-line options include corticosteroids (for example prednisone or dexamethasone) or intravenous immunoglobulin (IVIG); anti-D can be used in Rh-positive patients. Refractory disease may be treated with rituximab, splenectomy, or thrombopoietin receptor agonists such as eltrombopag or romiplostim. Platelet transfusion is generally reserved for life-threatening bleeds.

Prognosis and epidemiology vary. Many children experience spontaneous remission within months, while adults are more likely to have chronic disease but can respond to therapy. The incidence is about 1 to 6 per 100,000 per year, with a bimodal age distribution. Management is typically coordinated by hematology.