What is Idiopathic Thrombocytopenic Purpura (ITP)?

Idiopathic Thrombocytopenic Purpura (ITP) is a rare bleeding disorder. It affects both men and women, both children and adults; it can be mild or severe; acute and short-term or subtle and chronic (long-lasting). Other names for ITP are: Immune (or: Immunological) Thrombocytopenic Purpura, Idiopathic Thrombopenic Purpura, Essential Thrombocytopenia, Primary Thrombocytopenia, and Hemorrhagic Purpura.

2) What does the name "Idiopathic Thrombocytopenic Purpura" mean?

The word "idiopathic" is just a fancy way of saying that the cause of ITP is unknown. The term "thrombocytopenic" (from "thrombocytopenia") means "low platelet count". Finally, the word "purpura" means "bruising because of bleeding into the skin". One common form of bleeding into the skin (purpura) in platelet disorders is called "petechiae". These are tiny little reddish marks on the skin, resembling a rash.

3) What are the characteristics of Idiopathic Thrombocytopenic Purpura?

The main (and sometimes the only) feature of ITP is thrombocytopenia, i.e. a deficiency of platelets in the circulating blood. Platelets (thrombocytes) are tiny cellular blood components that help blood to clot. Platelets are the body's first line of defense against bleeding (primary hemostasis). Very commonly, ITP is mild and has no symptoms (asymptomatic thrombocytopenia).

4) So... what causes the bleeding tendency in Idiopathic Thrombocytopenic Purpura?

The bleeding tendency in ITP is caused by the insufficient number of platelets in the bloodstream. In over 60% of ITP cases, there is a low platelet count because platelets are prematurely removed from the circulation for destruction by the spleen. Why does this happen? The reasons are not clear (hence the term "idiopathic"), but they appear to be of autoimmune origin. This means that for some reason, the body's immune system is thrown out of whack, and tags its own platelets for destruction as if they were foreign pathogens. Sometimes (especially in acute, short-term ITP in children) a viral infection triggers this autoimmune response, but in most cases (as in chronic ITP in adults) the reason for the immune malfunction is unknown.

5) What are the symptoms of Idiopathic Thrombocytopenic Purpura?

When symptomatic, ITP manifests itself with essentially the same symptoms as any platelet disorder, whether quantitative or qualitative: spontaneous bleeding from the nose (epistaxis) and gums (gingival hemorrhage), blood in the urine and/or stools, unusually heavy menstruation (menorrhagia), abnormal bruising, and petechiae.

6) How is Idiopathic Thrombocytopenic Purpura diagnosed?

Laboratory tests that can diagnose ITP include a complete blood count (CBC), a peripheral smear, and coagulation tests (e.g. bleeding time). The important thing to remember is that ITP diagnosis is predominantly a diagnosis of exclusion, i.e. the physician will order tests to exclude underlying diseases that could be causing the thrombocytopenia. For example, in ITP, the bone marrow is normal; therefore, a normal bone marrow biopsy will exclude leukemia as the cause of the thrombocytopenia.

7) How is Idiopathic Thrombocytopenic Purpura treated?

When the platelet count is within safe limits and no bleeding is present, treatment will not be necessary. In acute ITP in children, ITP goes away by itself in about 85% of the cases within 6 months to a year from onset. Chronic ITP in adults can be more complicated. The primary aim of chronic ITP management is to achieve and maintain a safe platelet count. Therapeutic intervention may include, as necessary, corticosteroids, intravenous immunoglobulins, immunosuppressant medications, and splenectomy (surgical removal of the spleen).