Immune Thrombocytopenic Purpura (ITP)
An immune disorder that lowers platelets and causes easy bruising
Quick Facts
- Type: Autoimmune blood disorder
- Cause: Immune destruction of platelets
- Main signs: Easy bruising, tiny red spots, bleeding
- Course: Often self-limited in children; can be chronic in adults
Overview
Immune thrombocytopenic purpura (ITP) is a disorder in which the immune system mistakenly attacks and destroys platelets, the small blood cells that help blood clot. It also lowers the production of new platelets. With fewer platelets, the blood cannot clot normally, so people bruise and bleed more easily.
ITP can affect children and adults. In children, it often follows a viral illness and resolves on its own within weeks to months. In adults, it is more likely to become a long-term (chronic) condition. Many people have mild disease that needs only monitoring, while others require treatment to raise the platelet count and reduce bleeding risk.
Symptoms
Symptoms relate to a low platelet count and a tendency to bleed. Some people have no symptoms and are found to have a low platelet count on a routine blood test.
- Easy or excessive bruising
- Tiny flat red or purple spots on the skin (petechiae), often on the lower legs
- Bleeding from the gums or nose
- Blood in urine or stool
- Unusually heavy or prolonged menstrual periods
- Prolonged bleeding from small cuts
- Fatigue in some people
Seek emergency care for signs of serious bleeding, such as severe or uncontrolled bleeding, vomiting blood, a sudden severe headache, confusion, or weakness, which could indicate bleeding in the brain.
Causes
In ITP, the immune system produces antibodies that target platelets, marking them for destruction in the spleen. The trigger is often unknown, which is why it was historically called idiopathic. Recognized associations include:
- Viral infections: Especially in children, ITP may follow a viral illness.
- Other autoimmune conditions: Such as lupus.
- Certain infections: Including some chronic viral infections.
- Some medications: Which can occasionally trigger immune platelet destruction.
ITP is not contagious and is not caused by anything a person did.
Risk Factors
- Recent viral infection, particularly in children
- Being a younger woman (for chronic ITP in adults)
- Other autoimmune diseases
- Certain chronic infections
Diagnosis
ITP is diagnosed by finding a low platelet count and ruling out other causes. There is no single confirmatory test.
- Complete blood count (CBC): Shows a low platelet count, usually with normal red and white cells.
- Blood smear: Examining blood under a microscope to confirm the low count and check platelet appearance.
- Medical history and examination: To look for other causes of low platelets and signs of bleeding.
- Additional tests: Sometimes done to exclude infections or other conditions; a bone marrow test is occasionally needed in uncertain cases.
Treatment
Treatment depends on the platelet count, bleeding symptoms, age, and overall health. Many people with mild ITP need only observation.
- Watchful waiting: Monitoring without medication when bleeding risk is low, especially in children.
- Corticosteroids: Often the first treatment to reduce immune destruction of platelets.
- Intravenous immunoglobulin (IVIG): Used to raise the platelet count quickly, such as before a procedure or with active bleeding.
- Other medications: Drugs that stimulate platelet production or further suppress the immune attack for ongoing disease.
- Splenectomy: Removing the spleen may be considered for some chronic cases that do not respond to other treatments.
Treatment is tailored to the individual, with the goal of preventing bleeding rather than simply normalizing the count.
Prevention
ITP cannot usually be prevented because the immune trigger is often unknown. People with ITP can lower their bleeding risk by:
- Avoiding medications that affect platelets, such as aspirin and ibuprofen, unless advised by a clinician
- Avoiding contact sports or activities with a high injury risk when platelet counts are very low
- Telling all healthcare providers about the condition before procedures
- Attending regular follow-up to monitor platelet counts
When to See a Doctor
See a doctor if you notice unexplained bruising, tiny red spots on the skin, frequent nosebleeds or gum bleeding, or unusually heavy periods. Seek emergency care for heavy or uncontrolled bleeding, vomiting blood, blood in the urine or stool, or a sudden severe headache, confusion, or weakness, which could signal bleeding in the brain.
Frequently Asked Questions
What does ITP stand for?
ITP stands for immune (or idiopathic) thrombocytopenic purpura. It describes an immune disorder that lowers the platelet count (thrombocytopenia) and can cause purple bruising and spots on the skin (purpura).
Is ITP a serious or dangerous condition?
Many people have mild ITP that causes only bruising and needs little treatment. However, very low platelet counts can lead to serious bleeding. Severe or uncontrolled bleeding, or signs of bleeding in the brain such as a sudden severe headache or confusion, are emergencies.
Does ITP go away on its own?
In children, ITP often resolves on its own within weeks to a few months, frequently after a viral illness. In adults, it is more likely to become chronic, though many people manage it well with monitoring and treatment when needed.
What medications should I avoid with ITP?
It is best to avoid aspirin, ibuprofen, and other medications that interfere with platelets unless your doctor advises otherwise, because they can increase bleeding. Always check with your care team before starting new medicines or supplements.
Is ITP contagious or inherited?
No. ITP is not contagious and is not passed down through families. It is an autoimmune condition in which the body's own immune system attacks its platelets, often after a trigger that is not fully understood.
References
- National Heart, Lung, and Blood Institute (NHLBI). Immune Thrombocytopenia.
- MedlinePlus, U.S. National Library of Medicine. Immune thrombocytopenic purpura (ITP).
- Mayo Clinic. Immune thrombocytopenia (ITP).
- American Society of Hematology. Immune Thrombocytopenia (ITP).