Idiopathic thrombocytopenic purpura is an immune disorder in which the blood doesn’t clot normally. This condition is now more commonly referred to as immune thrombocytopenia (ITP).
ITP can cause excessive bruising and bleeding. An unusually low level of platelets, or thrombocytes, in the blood results in ITP.
Platelets are produced in the bone marrow. They help stop bleeding by clumping together to form a clot that seals cuts or small tears in blood vessel walls and tissues. If your blood doesn’t have enough platelets, it’s slow to clot. Internal bleeding or bleeding on or under the skin can result.
People with ITP often have many purple bruises called purpura on the skin or mucous membranes inside the mouth. These bruises may also appear as pinpoint-sized red or purple dots on the skin called petechiae. Petechiae often look like a rash.
ITP can occur in both children and adults. There appears to be differences at certain ages between women and men and the development of ITP. At younger ages, ITP may be more common in women. At older ages, it may be more common in men. Children are most likely to develop this condition after a general viral illness. Some specific viruses, such as chickenpox, mumps, and measles, have been linked to ITP as well.
The two main types of ITP are acute (short term) and chronic (long term).
Acute ITP is the most common form of the disorder in children. It usually lasts less than six months.
Chronic ITP lasts six months or longer. It’s most commonly seen in adults, although teenagers and younger children can also be affected.
The term “idiopathic,” used in the former name of the condition, means “of unknown cause.” In the past, it was used because the cause of ITP wasn’t well understood. However, it’s now clear that the immune system plays an important role in the development of ITP, thus its newer name, immune thrombocytopenia.
In ITP, the immune system produces antibodies against platelets. These platelets are marked for destruction and removal by the spleen, which lowers the platelet count. The immune system also appears to interfere with cells responsible for normal platelet production, which can further lower the number of platelets in the blood stream.
In children, ITP often develops acutely following a virus. In adults, ITP usually develops over time.
ITP can also be classified as primary, occurring on its own, or secondary, occurring alongside another condition. Autoimmune diseases, chronic infections, medications, pregnancy, and certain cancers are common secondary triggers.
ITP isn’t contagious and can’t be passed from one person to another.
The most common symptoms of ITP are:
- bruising easily
- pinpoint-sized petechiae, often on the lower legs
- spontaneous nosebleeds
- bleeding from the gums (for example, during dental work)
- blood in the urine
- blood in the stool
- abnormally heavy menstruation
- prolonged bleeding from cuts
- profuse bleeding during surgery
Some people with ITP have no symptoms.
Your doctor will perform a complete physical exam. They’ll ask you about your medical history and the medications you’re taking.
Your doctor will also order blood tests that include a complete blood count. The blood tests may also include tests to evaluate your liver and kidney function, depending on your symptoms. A follow-up blood test that checks for platelet antibodies may also be recommended.
Your doctor will request a blood smear, in which some of your blood is placed on a glass slide and viewed under a microscope to verify the number and appearance of platelets seen in the complete blood count.
If you have a low platelet count, your doctor may also order abone marrow test. If you have ITP, your bone marrow will be normal. This is because your platelets are destroyed in the bloodstream and spleen after they leave the bone marrow. If your bone marrow is abnormal, your low platelet count will likely be caused by another disease, rather than ITP.
Your doctor will choose your treatment based on the total number of platelets you have and on how often and how much you bleed. In some cases, treatment isn’t needed. For example, children that develop the acute form of ITP usually recover within six months or less without any treatment.
Adults with less severe cases of ITP may also not require treatment. However, your doctor will still want to monitor your platelet and red blood cell count to make sure you don’t need treatment in the future. Platelets counts that become too low put you at risk for spontaneous bleeding in the brain and other organs. Low red blood cell counts can also be a sign of internal bleeding.
If you or your child requires treatment, your doctor will likely prescribe medications as the first course of treatment. The most common medications used to treat ITP include:
Your doctor may prescribe a corticosteroid, such as prednisone (Rayos), which can increase your platelet count by decreasing the activity of your immune system.
Intravenous immunoglobulin (IVIg)
If your bleeding has reached a critical level or you’re going to have surgery and need to increase your platelet count quickly, you may be given intravenous immunoglobulin (IVIg).
This is for people who have Rh-positive blood. Like IVIg therapy, it can quickly increase the platelet count, and it may work even faster than IVIg. However, it can have serious side effects, so individuals should be carefully chosen for this treatment.
This is an antibody therapy that targets the immune cells responsible for producing the proteins that attack platelets. When this medication binds to those immune cells, known as B cells, they are destroyed. This means there are less B cells around, which means less cells available to make the proteins that attack platelets. However, it’s unclear if this treatment has long-term benefits.
Thrombopoietin receptor agonists
Thrombopoietin receptor agonists, including romiplostim (Nplate) and eltrombopag (Promacta), help prevent bruising and bleeding by causing your bone marrow to produce more platelets. Both of these medications have been approved by the U.S. Food and Drug Administration (FDA) for the treatment of low platelet counts due to chronic ITP.
If the above medications don’t improve your symptoms, your doctor may choose to prescribe other drugs, including:
General immunosuppressants inhibit the overall activity of the immune system. They don’t target specific components of the immune system related to ITP. These include:
- cyclophosphamide (Cytoxan)
- azathioprine (Imuran, Azasan)
- mycophenolate (CellCept)
However, they have significant side effects. So often they are used only in severe cases that haven’t responded to other treatments.
Helicobacter pylori, which is the bacteria that causes most peptic ulcers, has been associated with ITP in some people. Antibiotic therapy to eliminate H. pylori has been shown to help increase platelet counts in certain individuals.
If you have severe ITP and medication doesn’t improve your symptoms or platelet count, your doctor may advise surgery to remove your spleen. This is called a splenectomy. Your spleen is located in your upper left abdomen.
Splenectomy isn’t usually performed in children because of the high rate of spontaneous remission, or unexpected improvement. Having a splenectomy also increases the risk of certain bacterial infections in the future.
Severe or widespread ITP requires emergency treatment. This usually includes transfusions of concentrated platelets and intravenous administration of a corticosteroid such as methylprednisolone (Medrol), IVIg, or anti-D treatments.
Your doctor may also advise you to make some lifestyle changes, including the following:
- Avoid certain over-the-counter drugs that can affect platelet function, including aspirin, ibuprofen (Advil, Motrin), and the blood-thinning medication warfarin (Coumadin).
- Limit your intake of alcohol because consuming alcohol can adversely affect blood clotting.
- Choose low-impact activities instead of competitive sports or other high-impact activities to decrease your risk of injury and bleeding.
Treatment for pregnant women with ITP depends on the platelet count. If you have a mild case of ITP, you probably won’t need any treatment other than careful monitoring and regular blood tests.
If you have an extremely low platelet count and it’s late in the pregnancy, you’re more likely to experience serious, heavy bleeding during and after delivery. In these cases, your doctor will work with you to determine a treatment plan that will help maintain a safe platelet count without adversely affecting your baby. If you experience ITP along with other serious conditions of pregnancy, such as preeclampsia, you will need treatment as well.
Although most babies born to mothers with ITP aren’t affected by the disorder, some are born with or develop a low platelet count soon after birth. Treatment may be necessary for babies with very low platelet counts.
The most dangerous complication of ITP is bleeding, especially bleeding into the brain, which can be fatal. However, serious bleeding is rare.
The treatments for ITP can have more risks than the disease itself. The long-term use of corticosteroids can cause serious side effects, including:
- a loss of muscle mass
- an increased risk of infection
Surgery to remove the spleen permanently increases your risk of bacterial infections and the risk of becoming seriously ill if you get an infection. It’s important to watch for any symptoms of infection and report them to your doctor promptly.
In the majority of people with ITP, the condition isn’t serious or life-threatening.
Acute ITP in children often resolves within six months or less without treatment.
Chronic ITP can last for many years. People can live for many decades with the disease, even those with severe cases. Many people with ITP are able to manage their condition safely without any long-term complications or a decreased life span.