Idiopathic thrombocytopenic purpura (ITP)
Medically reviewed on Aug 9, 2017
Idiopathic thrombocytopenic purpura (ITP) is a disorder that can lead to easy or excessive bruising and bleeding. The bleeding results from unusually low levels of platelets — the cells that help blood clot.
Idiopathic thrombocytopenic purpura, which is also called immune thrombocytopenia, affects children and adults. Children often develop ITP after a viral infection and usually recover fully without treatment. In adults, the disorder is often long term.
If you don't have signs of bleeding and your platelet count isn't too low, you may not need any treatment. In rare cases, the number of platelets may be so low that dangerous internal bleeding occurs. Treatment options are available.
Idiopathic thrombocytopenic purpura (ITP) may have no signs and symptoms. When they do occur, they may 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
When to see a doctor
Make an appointment with your doctor if you or your child develops warning signs that worry you.
Bleeding that won't stop is a medical emergency. Seek immediate help if you or your child experiences bleeding that can't be controlled by the usual first-aid techniques, such as applying pressure to the area.
Petechiae may look like a rash and usually appear in clusters. Here they appear on a leg (A) and on an abdomen (B).
In some people thrombocytopenia is caused by the immune system mistakenly attacking and destroying platelets. If the cause of this immune reaction is unknown, the condition is called idiopathic thrombocytopenic purpura. Idiopathic means "of unknown cause."
In most children with ITP, the disorder follows a viral illness, such as the mumps or the flu. It may be that the infection triggers the immune system malfunction.
Increased breakdown of platelets
In people with ITP, antibodies produced by the immune system attach themselves to the platelets, marking the platelets for destruction. The spleen, which helps your body fight infection, recognizes the antibodies and removes the platelets from your system. The result of this case of mistaken identity is a lower number of circulating platelets than is normal.
A normal platelet count is generally between 150,000 and 450,000 platelets per microliter of circulating blood. People with ITP often have platelet counts below 20,000. Because platelets help the blood clot, as their number decreases, your risk of bleeding increases. The greatest risk is when your platelet count falls very low — below 10,000 platelets per microliter. At this point, internal bleeding may occur even without any injury.
Idiopathic thrombocytopenic purpura can occur in anyone at almost any age, but these factors increase the risk:
- Your sex. Women are two to three times more likely to develop ITP than men are.
- Recent viral infection. Many children with ITP develop the disorder after a viral illness, such as mumps, measles or a respiratory infection.
A rare complication of idiopathic thrombocytopenic purpura is bleeding into the brain, which can be fatal.
In pregnant women with ITP, the condition doesn't usually affect the baby. But the baby's platelet count should be tested soon after birth.
If you're pregnant and your platelet count is very low or you have bleeding, you have a greater risk of heavy bleeding during delivery. In such cases, you and your doctor may discuss treatment to maintain a stable platelet count, taking into account the effects on your baby.
To diagnose idiopathic thrombocytopenic purpura, your doctor will try to exclude other possible causes of bleeding and a low platelet count, such as an underlying illness or medications you or your child may be taking.
Your doctor will also ask you about your or your child's medical history, perform a physical exam and run one or more of the following tests:
- Complete blood count (CBC). This common blood test is used to determine the number of blood cells, including platelets, in a sample of blood. With ITP, white and red blood cell counts are usually normal, but the platelet count is low.
- Blood smear. This test is often used to confirm the number of platelets observed in a complete blood count. A sample of blood is placed on a slide and observed under a microscope.
Bone marrow exam. This test may be used to help identify the cause of a low platelet count, though the American Society of Hematology doesn't recommend this test for children with ITP.
Platelets are produced in the bone marrow — soft, spongy tissue in the center of large bones. In some cases, a sample of bone tissue and the enclosed marrow is removed in a procedure called a bone marrow biopsy. Or your doctor may do a bone marrow aspiration, which removes some of the liquid portion of the marrow. In many cases, both procedures are performed at the same time (bone marrow exam).
In people with ITP, the bone marrow will be normal because a low platelet count is caused by the destruction of platelets in the bloodstream and spleen — not by a problem with the bone marrow.
People with mild idiopathic thrombocytopenic purpura may need nothing more than regular monitoring and platelet checks. Children usually improve without treatment. Most adults with ITP will eventually need treatment, as the condition often becomes severe or long-term (chronic) ITP.
Treatment may include a number of approaches, such as medications to boost your platelet count or surgery to remove your spleen (splenectomy). Talk with your doctor about the risks and benefits of your treatment options. Some people find that the side effects of treatment are more burdensome than the effects of the disease itself.
Your doctor will talk with you about medications or supplements you take and whether you need to stop using any that might inhibit platelet function. Examples include aspirin, ibuprofen (Advil, Motrin IB, others), ginkgo biloba and warfarin (Coumadin).
Your doctor may prescribe one or more of the following medications to treat ITP:
Drugs that suppress your immune system. Your doctor will likely start you on an oral corticosteroid, such as prednisone. This drug may help raise your platelet count by decreasing the activity of your immune system. Once your platelet count is back to a safe level, you can gradually discontinue taking the drug under the direction of your doctor. In general, this takes about two to six weeks.
The problem is that many adults experience a relapse after discontinuing corticosteroids. A new course of corticosteroids may be pursued, but long-term use of these medications isn't recommended because of the risk of serious side effects. These include cataracts, high blood sugar, increased risk of infections and thinning of bones (osteoporosis).
- Injections to increase your blood count. If corticosteroids don't help, your doctor may give you an injection of immune globulin (IVIG). This drug may also be used if you have critical bleeding or need to quickly increase your blood count before surgery. The effect usually wears off in a couple of weeks. Possible side effects include headache, vomiting and low blood pressure.
- Drugs that boost platelet production. Thrombopoietin receptor agonists — such as romiplostim (Nplate) and eltrombopag (Promacta) — help your bone marrow produce more platelets. Possible side effects include headache, dizziness, nausea or vomiting, and an increased risk of blood clots.
- Other immune-suppressing drugs. Rituximab (Rituxan) helps reduce the immune system response that's damaging platelets, thus raising the platelet count. Possible side effects include low blood pressure, fever, sore throat and rash.
Although rare, severe bleeding can occur with ITP. Emergency care usually includes transfusions of platelet concentrates, intravenous corticosteroid (methylprednisolone) and intravenous immune globulin.
Treatments for resistant disease
If your condition persists despite treatment, your doctor may suggest other drugs that suppress the immune system or boost platelet production:
Removal of your spleen. If your condition is severe or persists despite initial drug treatment, your doctor may suggest surgical removal of your spleen (splenectomy). This quickly eliminates the main source of platelet destruction in your body and improves your platelet count, though it doesn't work for everyone. Serious post-surgical complications sometimes occur, and not having a spleen permanently increases your susceptibility to infection.
Splenectomy is rarely a treatment choice for children with ITP because they often get better without treatment.
- Other drugs. Azathioprine (Imuran, Azasan) has been used to treat ITP. But it can cause significant side effects, and its effectiveness has yet to be proved. Possible side effects include fever, headache, nausea and vomiting, and muscle pain.
Lifestyle and home remedies
If you have idiopathic thrombocytopenic purpura, try to:
- Avoid activities that could cause injury. Ask your doctor which activities are safe for you. Contact sports — such as boxing, martial arts and football — carry a high risk of injury.
- Drink alcohol in moderation, if at all. Alcohol slows the production of platelets in your body. Ask your doctor whether it's OK for you to drink alcohol.
- Watch for signs of infection. If you've had your spleen removed, be alert for any signs of infection, including fever, and seek prompt treatment. Infection in someone who has had a splenectomy may be more severe than in someone who still has a spleen.
- Use caution with over-the-counter medications. Nonprescription drugs such as aspirin and ibuprofen (Advil, Motrin IB, others) can impair platelet function.
Preparing for an appointment
Because a low platelet count may not cause symptoms, the problem is often discovered when you have a blood test for another reason. In order to diagnose idiopathic thrombocytopenic purpura, your doctor is likely to order further blood tests that require drawing a small amount of blood from a vein in an arm. He or she may also refer you to a specialist in blood diseases (hematologist).
What you can do
Here are some steps you can take to get ready for your appointment:
- List any symptoms you're experiencing, including those that seem unrelated to the reason for which you scheduled the appointment.
- List key personal information, including major stresses, life changes, and recent illnesses or medical procedures, such as a blood transfusion.
- List all medications, vitamins and supplements that you're taking, including doses. Note whether you've recently used antibiotics, tonic water, herbal preparations and heparin, which can be linked to thrombocytopenia.
- Ask a family member or friend to come with you. It addition to offering support, he or she can write down information from your doctor or other clinic staff during the appointment.
- List questions to ask your doctor. Preparing a list of questions can help you make the most of your time together.
For ITP some questions you may want to ask include:
- How many platelets do I have in my blood?
- Is my platelet count dangerously low?
- What is causing my ITP?
- Do I need more tests?
- Is this condition temporary or long lasting?
- What treatments are available, and what do you recommend?
- What will happen if I do nothing?
- What are the possible side effects of the treatments you're suggesting?
- Are there any restrictions that I need to follow?
- Is there a generic alternative to the medicine you're prescribing?
- Do you have any brochures or other printed material that I can take with me? What websites do you recommend?