About Idiopathic Thrombocytopenic Purpura (ITP)

What Is Idiopathic Thrombocytopenic Purpura (ITP)?

Idiopathic thrombocytopenic purpura [ih-dee-oh-PATH-ik throm-boh-sy-toh-puh-NEE-ik PUR-pyuh-ruh] (ITP), also known as immune thrombocytopenia, is an autoimmune disorder characterized by a drop in the number of platelets in the blood. Platelets are important for blood clotting, and a low platelet count can lead to easy bruising and bleeding. In ITP, the immune system mistakenly attacks and destroys platelets, leading to their reduced lifespan.

The exact cause of ITP is "idiopathic" which means there is no known or clear cause. It can occur in both children and adults, with symptoms ranging from mild to severe. Common symptoms include petechiae [peh-TEE-kee-ee] which are small red or purple spots on the skin, easy bruising, nosebleeds, and prolonged bleeding from cuts or injuries. Treatment options for ITP aim to increase platelet count and manage symptoms, and may include medications, such as corticosteroids (lab-made drugs that copy the natural hormone cortisol made by your adrenal glands) or immunosuppressants (drugs that slow down or decrease the activity of the body's immune system), and in some cases, splenectomy (removal of the spleen).

ITP may be acute (short term) or chronic (long term). Acute ITP often lasts less than 12 months and is more common in children, while chronic ITP lasts 12 months or longer and is more common in adults.

Idiopathic Thrombocytopenic Purpura Causes and Risk Factors

Idiopathic thrombocytopenic purpura is a complex blood (hematologic) disorder characterized by low platelet count. The exact root cause of ITP is not fully understood, but several theories have been proposed:

Autoimmune destruction: ITP is mainly caused by the immune system attacking platelets by mistake. The body’s immune system sees platelets as harmful and makes antibodies that target and destroy them.
Reduced platelet production: In some cases, ITP also affects how well platelets are made. This happens when the cells in the bone marrow that make platelets, called megakaryocytes, are not working as well as they should.

Risk factors that cannot be changed or influenced include:

Age: People older than 60 years are at a higher risk of developing ITP.

There are no well-established lifestyle changes that are known to prevent ITP. However, some infections, medical conditions, and medicines can trigger secondary immune thrombocytopenia or affect how ITP develops or is managed.

Infections and underlying conditions: ITP may occur after certain infections, especially viral infections in children. In some people, ITP may be associated with infections such as Helicobacter pylori (H. pylori), hepatitis C, or HIV, or with autoimmune conditions such as lupus. When an underlying trigger is found, treating that condition may help improve platelet counts in some cases.
Medicines: Some medicines can rarely cause immune-related low platelet counts or worsen bleeding risk. Examples include heparin, some antibiotics, anticonvulsants, chemotherapy medicines, and drugs that affect platelet function, such as aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs). Do not stop or change a prescribed medicine without talking with a health care professional.

It's important to note that while these factors may be linked with an increased risk of developing ITP, they do not mean it will happen. If you have concerns about your risk for ITP or its cause, it's best to consult with your healthcare professional for personalized advice.

Idiopathic Thrombocytopenic Purpura Symptoms

Some people with idiopathic thrombocytopenic purpura (ITP), also called immune thrombocytopenia, may not have noticeable symptoms. When symptoms do occur, they are usually related to bleeding caused by a low platelet count. Symptoms may include:

Petechiae and purpura: Petechiae are small, flat red, purple, or brown spots under the skin caused by bleeding from tiny blood vessels. Purpura are larger areas of bleeding under the skin that may look like bruises.
Easy or unexplained bruising: Bruises may appear after minor bumps or without a clear injury.
Bleeding from the nose or gums: Nosebleeds or gum bleeding may happen more often or last longer than usual.

Other symptoms or warning signs may include:

Heavy menstrual bleeding: Menstrual periods may be heavier or last longer than usual.
Blood in urine or stool: Blood may appear in urine, or stool may look bloody, black, or tarry.
Hematomas: A hematoma is a collection of clotted or partly clotted blood under the skin that may look or feel like a lump.
Bleeding that lasts longer than expected: Cuts, dental work, surgery, or minor injuries may bleed more than usual.
Fatigue, pale skin, dizziness, or shortness of breath: These symptoms may occur if bleeding leads to anemia.

These symptoms can also be caused by conditions other than ITP. Contact a health care professional if you have new or unexplained bruising or bleeding. Seek urgent medical care for bleeding that does not stop with usual first aid, severe or unusual headache, confusion, weakness, or any symptoms that suggest serious internal bleeding.

How Is Idiopathic Thrombocytopenic Purpura Diagnosed?

There is no single test that can confirm idiopathic thrombocytopenic purpura (ITP), also called immune thrombocytopenia. Health care providers diagnose ITP by checking for a low platelet count and ruling out other possible causes of low platelets or bleeding. The diagnostic process may include:

Medical history and physical exam: Your health care provider may ask about bleeding symptoms, recent infections, vaccines, medical conditions, family history, and all prescription, over-the-counter, herbal, or supplement products you take. They may also look for petechiae, purpura, bruising, nose or gum bleeding, and signs of other conditions.
Complete blood count (CBC): A CBC measures the platelet count and checks red and white blood cells. In ITP, the platelet count is low, while other blood cell counts are often normal unless bleeding has caused anemia or another condition is present.
Peripheral blood smear: A blood smear lets a laboratory professional look at the size, shape, and appearance of platelets and other blood cells under a microscope. This can help rule out other causes of thrombocytopenia.

Additional tests may be recommended based on your history, symptoms, and initial test results. These may include:

Tests for secondary causes: Your provider may order tests for infections such as HIV, hepatitis C, hepatitis B, or Helicobacter pylori (H. pylori), or tests for autoimmune or immune conditions when these are suspected.
Bone marrow tests: Bone marrow aspiration or biopsy is not routinely needed to diagnose typical ITP. It may be recommended if the diagnosis is unclear, if other blood cell counts are abnormal, if another bone marrow condition is suspected, or if treatment is not working as expected.

Follow-up platelet counts help monitor whether ITP is improving, staying stable, or worsening. Your health care provider may refer you to a hematologist, a doctor who specializes in blood disorders, especially if platelet counts are very low, symptoms are significant, the diagnosis is uncertain, or treatment is needed.

Idiopathic Thrombocytopenic Purpura Treatment Options

Treatment for idiopathic thrombocytopenic purpura (ITP), also called immune thrombocytopenia, depends on the platelet count, bleeding symptoms, age, other medical conditions, medicines that affect bleeding risk, and personal preferences. The goal is not always to return the platelet count to normal. The goal is to raise the platelet count enough to lower the risk of serious bleeding while avoiding unnecessary treatment side effects.

Observation and medicines:

Observation: People with mild ITP and little or no bleeding may not need medicine right away. They may be monitored with repeat platelet counts and instructions about when to seek care.
Corticosteroids: Corticosteroids, such as prednisone or dexamethasone, are often used as an initial treatment. They can raise platelet counts by reducing immune-related platelet destruction, but they are usually used for a limited time because side effects can occur.
Intravenous immunoglobulin (IVIG): IVIG may be used when a faster platelet increase is needed, such as before a procedure or when bleeding risk is higher. Its effect is usually temporary.
Second-line medicines: If ITP does not improve or returns after initial treatment, options may include thrombopoietin receptor agonists, which help the bone marrow make more platelets; rituximab, which reduces certain immune cells involved in platelet destruction; or other medicines chosen by a specialist.

Procedures and urgent treatment:

Platelet transfusion: Platelet transfusions are usually reserved for serious or life-threatening bleeding because transfused platelets may be destroyed quickly in ITP. They are often used with other treatments, such as IVIG or corticosteroids, in urgent situations.
Splenectomy: Surgery to remove the spleen may help some adults with persistent or chronic ITP, but it is generally considered after other options because it is not effective for everyone and can increase the risk of certain infections.

Self-care and safety steps:

Avoid activities that increase the risk of injury or bleeding, such as contact sports, unless your health care provider says they are safe for your platelet count.
Ask your health care provider before taking medicines or supplements that can increase bleeding risk, such as aspirin, ibuprofen or other nonsteroidal anti-inflammatory drugs (NSAIDs), blood thinners, or herbal supplements such as ginkgo.

Seek urgent medical care for bleeding that does not stop, blood in vomit, urine, or stool, severe headache, confusion, weakness, vision changes, or any symptoms that may suggest serious internal bleeding.

Your health care provider can help weigh the benefits and risks of each treatment option. Treatment choices may differ for children, adults, pregnancy, planned surgery or dental work, and people with other conditions or medicines that affect bleeding risk.