Idiopathic thrombocytopenic purpura (ITP), also called immune thrombocytopenic purpura, is a blood-clotting disorder that can lead to easy or excessive bruising and bleeding. ITP results from unusually low levels of platelets — the cells that help your blood clot.

Idiopathic thrombocytopenic purpura affects both children and adults. Children often develop idiopathic thrombocytopenic purpura after a viral infection and usually recover fully without treatment. In adults, however, the disorder is often chronic.

Treatment of idiopathic thrombocytopenic purpura depends on your symptoms and platelet count. If you don't have signs of bleeding and your platelet count isn't too low, treatment for idiopathic thrombocytopenic purpura usually isn't necessary. More serious cases may be treated with medications or, in critical situations, with surgery.

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Petechiae

Some people with a low platelet count have no symptoms. When signs and symptoms do occur, they may include:

• Easy or excessive bruising (purpura) — your skin naturally bruises and bleeds more easily as you age, but this shouldn't be confused with ITP
• Superficial bleeding into your skin that appears as a rash of pinpoint-sized reddish-purple spots (petechiae), usually on your lower legs
• Prolonged bleeding from cuts
• Spontaneous bleeding from your gums or nose
• Blood in urine or stools
• Unusually heavy menstrual flows
• Profuse bleeding during surgery

When to see a doctor
If you or your child has abnormal bleeding or bruising, or develops a rash of pinpoint-sized red spots, see your doctor. It's also important to seek medical advice if you're a woman and suddenly develop increased menstrual bleeding.

Serious or widespread bleeding indicates an emergency and requires immediate care.

The exact cause of ITP isn't known. For that reason it's referred to as idiopathic — meaning "of unknown cause." It is known, however, that in people with idiopathic thrombocytopenic purpura, the immune system malfunctions and begins attacking platelets as if they were foreign substances.

Antibodies produced by your 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 platelets than normal.

Ordinarily, you have anywhere from 150,000 to 450,000 platelets per microliter of circulating blood. As the number of platelets 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 despite a lack of any injury, although this is rare.

In most children with ITP, the disorder follows a viral illness, such as the mumps or the flu. It may be that an infection sets off the immune system, triggering it to malfunction. But ITP in adults isn't linked to infections.

ITP is a fairly common blood disorder and can strike anyone at almost any age, but these factors increase your risk:

• Your sex. Girls and younger women are about twice as likely to develop ITP as men are, but the gap narrows as people age.
• Age. Once considered a young person's disease, ITP is actually far more common in people older than 60 than it is in younger adults.
• Recent viral infection. Many children with ITP develop the disorder after a viral illness, such as mumps, measles or a respiratory infection. In most children, ITP clears on its own within two to eight weeks.

The biggest risk associated with idiopathic thrombocytopenic purpura is bleeding, especially bleeding into the brain (intracranial hemorrhage), which can be fatal. Major bleeding is rare with ITP, however. Complications are more likely to arise from the treatments — corticosteroids and surgery — used for chronic or severe ITP. In fact, many therapies pose more serious potential risks than does the disease.

Long-term use of corticosteroids can cause serious side effects, including osteoporosis, cataracts, loss of muscle mass and increased risk of infection. Removal of your spleen (splenectomy), which may be performed if corticosteroids aren't working, also makes you permanently more vulnerable to infection, although the risk of an overwhelming infection in a healthy person who has had a splenectomy is small.

Pregnancy
Pregnant women with mild ITP usually have a normal pregnancy and delivery, though antibodies to platelets can cross the placenta and affect the baby's platelet count. In some cases, a baby may be born with a low number of platelets. If this happens, your baby's doctor will want to monitor your child for several days. It's likely that your baby's platelet count will improve without treatment, but if the count is very low, treatment can help speed recovery.

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.

Because a low platelet count may not cause symptoms, the problem is often discovered when you have a blood test for another reason. If your doctor thinks you might have ITP, you are likely to have further blood tests that require drawing a small amount of blood from a vein in your arm. You are also likely to be referred to a doctor who specializes in blood disorders (hematologist) for further evaluation and treatment.

Appointments, even with specialists, can be brief, and there's often a lot of ground to cover, so it can help to be well prepared. Here are some tips to help you get ready for your appointment:

What you can do

• Write down all your symptoms — even those that seem unrelated to your current problem. Include key personal information, such as major stresses or recent life changes.
• Bring a list of all medications, including vitamins, herbs and over-the-counter drugs, that you're taking. Even better, bring the original bottles and a written list of the dosages and directions.
• If possible, bring along a family member or friend. It can be difficult to absorb all the information provided to you during an appointment. The person who accompanies you may remember something that you forgot or missed.
• Write down questions that you want to ask your doctor. Don't be afraid to ask questions or to speak up when you don't understand something your doctor says. Start with the problems that concern you most. If you run out of time, ask to speak with a nurse or physician's assistant or leave a message for your doctor.

Questions you may want to ask include:

• What tests are needed to confirm the diagnosis?
• Is this condition temporary or chronic?
• What is the best course of action?
• What will happen if I do nothing?
• What are the possible side effects of the treatments you're suggesting?
• How can I avoid those side effects?
• What kinds of alternative treatments exist?
• Can you refer me to a Web site or other source so I can learn more about this condition?

Doctors usually diagnose idiopathic thrombocytopenic purpura by excluding other possible causes of bleeding and a low platelet count, such as an underlying illness or medications you may be taking. If no other underlying problem is causing your signs and symptoms, then a diagnosis of ITP may be made.

In addition to taking your medical history and performing a physical exam, your doctor may order the following tests when checking for ITP:

• Complete blood count. This common blood test is used to determine the number of white and red blood cells and platelets in a sample of your blood. With ITP, white and red blood cell counts are usually normal, but the platelet count is low.
• Blood smear. A sample of your blood is placed on a slide and observed under a microscope. This test is often used to confirm the number of platelets observed in a complete blood count.

• Bone marrow examination. Another test that may help identify the cause of a low platelet count is a bone marrow exam. Platelets are produced in your bone marrow — soft, spongy tissue in the center of your large bones. In some cases, a sample of solid bone marrow is removed in a procedure called a bone marrow biopsy. Or, you may have a bone marrow aspiration, which removes the liquid portion of your marrow. In many cases, both procedures are performed at the same time (bone marrow exam). Both the liquid and solid bone marrow samples are frequently taken from the same place on the back of one of your hipbones. A needle is inserted into the bone through an incision.

  If you have ITP, your bone marrow will be normal because your low platelet count is caused by the destruction of platelets in your bloodstream and spleen — not by a problem with the bone marrow.

Idiopathic thrombocytopenic purpura is usually treated by a hematologist, a doctor who specializes in blood disorders. The goal of treating ITP is to ensure a safe platelet count and prevent bleeding complications while minimizing treatment side effects.

Because of the potential complications of both the disease and its treatment, it's important for you and your doctor to carefully weigh the benefits and risks of treatment. For example, some people find that the side effects of treatment are more burdensome than the effects of the disease itself. Treatment decisions are usually based on:

• Severity of signs and symptoms (active bleeding is usually an indication for treatment)
• Platelet count — even relatively low counts (less than 30,000 units per microliter of blood) may not merit treatment, especially if you have no active bleeding and have a fairly sedentary lifestyle
• Age
• Risk of bleeding relative to lifestyle, such as participation in sports or other vigorous physical activities that may predispose you to injury
• Risk of bleeding based on other medical conditions (high blood pressure, infections, alcoholism, chronic liver disease, peptic ulcer) or medications such as aspirin
• Potential side effects of ITP therapies
• Your own preferences

In children, idiopathic thrombocytopenic purpura usually runs its course without the need for treatment. About 80 percent of children with idiopathic thrombocytopenic purpura recover completely within six months. Even in children who develop chronic ITP, complete recovery may still occur, even years later.

Adults with mild cases of ITP may require nothing more than regular monitoring and platelet checks. But if your symptoms are troublesome and your platelet count is low in relation to your lifestyle and risk of bleeding, you and your doctor may opt for treatment. Treatment usually consists of medications and, sometimes, surgery (splenectomy). Your doctor may also have you discontinue certain drugs that can further inhibit platelet function, such as aspirin, ibuprofen (Advil, Motrin, others) and the blood-thinning medication warfarin (Coumadin).

Medications
Common medications used to treat idiopathic thrombocytopenic purpura include:

• Corticosteroids. The first line of therapy for ITP is a corticosteroid, usually prednisone, which can 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 four to six weeks.

  The problem is that about 70 percent of 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, including cataracts, high blood sugar, increased risk of infections and loss of calcium from your bones (osteoporosis). You and your doctor will want to weigh the benefits of the medication against these risks. If you've taken corticosteroids for longer than three months, your doctor will likely recommend that you take calcium and vitamin D supplements to help maintain your bone density.

• Intravenous immune globulin (IVIG). If you have critical bleeding or need to quickly increase your blood count before an operation, you may receive medications such as immune globulin through a needle placed in your vein. These medications are quick and effective, but their benefits usually wear off in a couple of weeks.

Surgery
If you have severe ITP and an initial course of prednisone hasn't helped, surgical removal of your spleen (splenectomy) may be an option. This eliminates the main source of platelet destruction in your body and improves your platelet count within a few weeks. Splenectomy for ITP is not as routinely performed as it once was, however. Serious post-surgical complications sometimes occur, and not having a spleen permanently increases your susceptibility to infection. What's more, some people relapse even after splenectomy.

Splenectomy is rarely performed in children because of their high rate of spontaneous remission.

Emergency treatment
Although rare, severe bleeding can occur in anyone with ITP, regardless of age or platelet count. Severe or widespread bleeding is life-threatening and demands emergency care. This usually includes transfusions of platelet concentrates, intravenous methylprednisolone (a type of corticosteroid) and intravenous immune globulin.

Other treatments
If neither the initial round of corticosteroids nor a splenectomy has helped you achieve remission and your symptoms are severe, your doctor may recommend another course of corticosteroids, usually at the lowest effective dose.

Other possible treatments include:

• Immunosuppressant drugs. Medications that suppress the immune system, such as rituximab (Rituxan) — the most commonly used of this group — cyclophosphamide (Cytoxan) and azathioprine (Imuran) have been used to treat ITP, but they can cause significant side effects, and their effectiveness has yet to be proved.
• Experimental drugs. New medications that increase platelet production, especially eltrombopag and AMG 531, are being studied in clinical trials. Although they appear to be well tolerated, questions about long-term side effects remain.
• H. pylori treatment. A number of people with ITP are also infected with Helicobacter pylori (H. pylori), the same bacteria that cause most peptic ulcers. Eliminating the bacteria has helped increase platelet count in some people, but the results for this type of therapy are inconsistent and need to be studied further.

If you have idiopathic thrombocytopenic purpura, the following steps may help control your risk of bleeding and other complications:

• Avoid platelet-impairing medications. Over-the-counter drugs such as aspirin and ibuprofen (Advil, Motrin, others) can impair platelet function.
• Limit alcohol. Excessive alcohol intake can adversely affect blood clotting.
• Choose low-impact physical activities. Your doctor may recommend avoiding competitive sports or other activities that might increase the risk of injury and bleeding.
• 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's had a splenectomy may be more severe, last longer and have more serious implications than in someone who still has an intact spleen.