Immune thrombocytopenic purpura (ITP) is a clinical syndrome in which fewer circulating platelets (thrombocytopenia) (see the image below) manifests as a bleeding tendency, easy bruising (purpura), or extravasation of blood from capillaries into skin and mucous membranes (Kessler & Nagalla: 2019).
ITP, also known as idiopathic thrombocytopenic purpura, is a type of thrombocytopenic purpura that displays an isolated low platelet count with normal bone marrow and the absence of other causes of low platelets. It causes a characteristic purpuric rash and an increased tendency to bleed.
Two distinct clinical syndromes manifest as an acute condition in children and a chronic condition in adults. The acute form often follows an infection and has a spontaneous resolution within two months. ITP is diagnosed by a low platelet count in a complete blood count (a common blood test). However, since the diagnosis depends on the exclusion of other causes of a low platelet count, additional investigations (such as a bone marrow biopsy) may be necessary to confirm if the symptoms are indicative of ITP. In mild cases, only careful observation may be required but very low counts or significant bleeding may prompt treatment with corticosteroids, intravenous immunoglobulin, anti-D immunoglobulin, or immunosuppressive medications. Refractory ITP (not responsive to conventional treatment) may require a splenectomy (the surgical removal of the spleen). Platelet transfusions may be used in severe bleeding and a very low count. Sometimes the body may compensate by making abnormally large platelets.
There are currently three classifications of ITP:
- Newly diagnosed (also referred to as acute) ITP: This form of ITP usually lasts less than three months and mostly affects children between the ages of 2 and 6, typically occurring shortly after a viral infection. Most children with acute ITP recover without treatment and their platelet counts eventually rise to normal levels.
- Persistent ITP: In this case the disease has been present for 3 to 12 months, with no spontaneous correction or remission on its own. It remains persistent even after several trials of treatment.
- Chronic / long-term ITP: Lasts for more than 12 months, usually strikes adults between the ages of 20 and 40 and requires medical treatment to restore normal platelet levels. Chronic ITP is three times more common in women than men. Typically, a person has weeks or months of mild to moderate abnormal bleeding before seeing a doctor.
There are three main methods used to diagnose Immune thrombocytopenic purpura:
- A blood platelet count: Doctors always order this test first. ITP is one of the causes of a low platelet count (thrombocytopenia).
- Other blood tests: Several different blood tests may be done, including a test for HIV and hepatitis C.
ITP Treatment Options
The two most common forms of treatment are steroids and intravenous gamma globulin.
Steroids for ITP
Steroids help prevent bleeding by decreasing the rate of platelet destruction. Steroids, if effective, will result in an increase in platelet counts seen within two to three weeks. Side effects may include irritability, stomach irritation, weight gain, hypertension and acne.
Intravenous Gamma Globulin (IVGG) for ITP
Intravenous gamma globulin (IVGG) is a protein that contains many antibodies and slows the destruction of platelets. IVGG works quicker than steroids (within 24 to 48 hours).
Other Treatments for ITP
Other treatment options may include:
- Rh immune globulin: Temporarily stops the spleen from destroying platelets.
- Medication changes: If we suspect that the child’s medication is causing the ITP, we will recommend discontinuing or changing the medication.
- Infection treatment: If an infection is causing the ITP, then treating the infection may result in higher platelet counts.
- Splenectomy: In some cases, the child’s spleen may need to be removed, since this is the most active site of platelet destruction.
- Hormone therapy: Teenage girls may need to take hormones to stop their menstrual cycle when their platelets are low if excessive bleeding occurs.
“It is much more important to know what sort of patient has a disease, rather than what sort of disease a patient has.”