Idiopathic Thrombocytopenic Purpura (ITP)

What is idiopathic thrombocytopenic purpura (ITP)?

Idiopathic thrombocytopenic purpura (ITP) is a bleeding disorder in which the immune system destroys platelets – which are necessary for normal blood clotting – leading to easy or excessive bruising and bleeding. Though this condition is characterized by a low platelet count, patients still maintain normal bone marrow and an absence of other causes of thrombocytopenia. Fortunately, ITP has a very low mortality rate.

ITP occurs in about 1-5 out of every 10,000.

What are the symptoms of ITP?

ITP may show no signs or symptoms, but if symptoms arise, they include:

• Easy or excessive bruising (purpura)
• Superficial bleeding into the skin that appears as a rash of pinpoint-sized reddish-purple spots (petechiae), usually on the lower legs
• Bleeding from the gums or nose
• Blood in urine or stools
• Unusually heavy menstrual flow for women

What are the causes of ITP?

ITP is not familial, meaning it is extremely unlikely for one to inherit the disease. Although the exact etiology of the disease is unknown, platelet destruction mediated by antibodies in the spleen is associated with the low platelet levels that are characteristic of ITP.

ITP occurs when certain immune system cells produce antibodies against platelets. In children, the disease sometimes follows a viral infection, such as the mumps or the flu. In adults, it is more often a chronic disease and can occur after a viral infection, with use of certain drugs, during pregnancy, or as part of an immune disorder. If the cause of this immune reaction is unknown, the condition is called idiopathic thrombocytopenic purpura. Idiopathic means “of unknown cause.”

How is ITP diagnosed?

To diagnose ITP, medical professionals will generally look at the patient’s medical history and symptoms to exclude other possible causes of bleeding and low platelet counts. They will conduct a physical exam and issue some laboratory tests to make a diagnosis, such as molecular genetics tests, as FCGR2C genes are associated with this disease, or blood tests and blood smear tests to check platelet counts. A bone marrow aspiration or biopsy may also be done.

What treatment options are available for ITP?

In children, the disease usually goes away without treatment, but some children may need treatment. Adults are usually started on a steroid medicine called prednisone. In some cases, surgery to remove the spleen is recommended. This increases the platelet count in about half of people.

However, other drug treatments are usually recommended instead, such as:

• Danazol (Danocrine) taken orally
• Infusions of high-dose gamma globulin (an immune factor)
• Drugs that suppress the immune system
• Anti-RhD therapy for people with certain blood types
• Drugs that stimulate the bone marrow to make more platelets

Where can I find more information about idiopathic thrombocytopenic purpura (ITP)?

• NIH
• The Platelet Disorder Support Association
• Orphanet
• Mayo Clinic