idiopathic thrombocytopenic purpura
Platelets are also called thrombocytes, and are made in the bone marrow (along with other kinds of blood cells). Platelets circulate through the blood vessels and help stop bleeding by sticking together (clotting) to seal small cuts or breaks.
Idiopathic means that the cause of the disease or condition is not known. Thrombocytopenic means there is a lower-than-normal number of platelets in the blood. Purpura are purple bruises caused by bleeding under the skin. More extensive bleeding can create a three-dimensional mass called a hematoma.
People who have ITP often have purple bruises that appear on the skin or on the mucous membranes (for example, in the mouth). The bruises mean that bleeding has occurred in small blood vessels under the skin. A person who has ITP also may have bleeding that results in tiny red or purple dots on the skin. These dots, often seen on the lower legs, are called petechiae. Petechiae may look like a rash.
People with ITP may have nosebleeds, bleeding from the gums when they have dental work done, or other bleeding that is hard to stop. Women with ITP may have heavy menstrual bleeding.
Bleeding in the brain as a result of ITP is very rare, but can be life threatening if it occurs.
In most cases, the body's immune system is thought to cause ITP. Normally the immune system helps the body fight off infections and diseases, but if you have ITP, your immune system attacks and destroys its own platelets – for an unknown reason.
Types of idiopathic thrombocytopenic purpura
There are two types of ITP: acute (temporary or short-term) and chronic (long-lasting).
Acute ITP generally lasts less than 6 months. It mainly occurs in children, both boys and girls, and is the most common type of ITP. It often occurs after an infection caused by a virus.
Chronic ITP is long-lasting (6 months or longer) and mostly affects adults. However, some teenagers and even younger children can get this type of ITP. Chronic ITP affects women 2 to 3 times more often than men. Treatment depends on how severe the bleeding symptoms are and the platelet count. In mild cases, treatment may not be needed.
For most children and adults, ITP isn't a serious or life-threatening condition.
Acute ITP in children often goes away on its own within a few weeks or months and doesn't return. In 80 percent of children who have ITP, the platelet count returns to normal within 6 to 12 months. Treatment may not be needed. A small number of children, about 5 percent, whose ITP doesn't go away on its own may need to have further medical or surgical treatment.
Chronic ITP will vary with each individual and can last many years. Even people who have severe forms of chronic ITP can live for decades. Most people with chronic ITP are able at some point to stop treatment and keep a safe platelet count.
In most cases, it's believed that the body's immune system causes idiopathic thrombocytopenic purpura (ITP). Normally, the immune system makes antibodies to fight off germs or other harmful things that enter the body. In ITP, however, the immune system treats your own platelets as if they were invaders in the body, attacking and destroying them.
Children who get the acute (temporary) type of ITP often have had a recent viral infection. It is possible that the infection somehow triggers or sets off the immune reaction that leads to ITP in these children. ITP in adults, on the other hand, doesn't seem to be linked to infections.
Who is at risk?Both children and adults can develop idiopathic thrombocytopenic purpura (ITP).
Children usually get the acute (temporary) type of ITP. This type of ITP often develops after an infection caused by a virus. Adults tend to get the chronic (long-lasting) type of ITP. Women are 2 to 3 times more likely than men to get chronic ITP.
ITP is a fairly common blood disorder, with 50 to 150 new cases per every 1 million people each year; about half of these cases are in children. However, the number of cases of ITP is increasing because routine blood tests that show a low platelet count are being done more often.
You can't catch ITP from another person.
Signs and symptoms
Having a low platelet count doesn't cause symptoms. The bleeding caused by a low platelet count may have the following signs or symptoms.
Any kind of bleeding that is hard to stop could be a sign of ITP. This includes heavy menstrual bleeding in women.
Bleeding in the brain is rare, and the symptoms of bleeding in the brain may vary in severity.
A low number of platelets won't cause pain, fatigue (tiredness), difficulty concentrating, or any other symptoms.
To diagnose idiopathic thrombocytopenic purpura (ITP), your doctor must first be certain that your low platelet count is not caused by other conditions, such as HIV infection or lupus, or by medicines (for example, chemotherapy drugs or aspirin). Your doctor will ask about your medical history, do a physical exam, and order blood tests.
Your medical history includes information about:
Your doctor will give you a physical exam and look for signs of bleeding and infection.
He or she also will order blood tests to measure the platelet count in your blood. These tests usually include:
If blood tests show that you have a low number of platelets, your doctor may need to order more tests to confirm a diagnosis of ITP. For example, bone marrow tests may be used to see if the large cells that make platelets look normal. (These large cells are called megakaryocytes.)
Some people with mild ITP have few or no signs of bleeding. In that case, they might be diagnosed only after a blood test done for another reason shows that they have a low number of platelets.
Treatment for idiopathic thrombocytopenic purpura (ITP) is based on how much and how often you are bleeding and your platelet count. Medicines are often used as the first course of treatment. Treatments used for children and adults are similar.
Adults with ITP who have very low platelet counts or problems with bleeding are usually treated. Adults who have milder cases of ITP may not need any treatment, other than monitoring their symptoms and platelet counts.
The acute (short-term) type of ITP that occurs in children often goes away within a few weeks or months. Children who have bleeding symptoms, other than merely bruising (purpura), are usually treated. Milder cases in children may not need treatment other than monitoring and follow-up to be sure platelet counts return to normal.
If treatment is needed for adults or children who have ITP, medicines are usually used first. Corticosteroids, such as prednisone, are commonly used to treat ITP. These medicines, called steroids for short, help raise the platelet count in the blood by lowering the activity of the immune system. However, steroids have a number of side effects, and some people relapse (get worse) when treatment ends.
Some medicines used to help raise the platelet count are given through a needle in a vein. These medicines include immunoglobulin and anti-Rh (D) immunoglobulin.
Experimental medicines may be tried if these treatments don't help. Medicines may be used along with a procedure to remove the spleen, called splenectomy.
Removal of the spleen (splenectomy)
If necessary, the spleen will be removed surgically. This organ is located in the upper left abdomen and is about the size of a golf ball in children and a baseball in adults. If ITP has not responded to steroids, removing the spleen will reduce the destruction of platelets, but it also may make you more likely to get certain types of infections. If your spleen is removed, discuss with your doctor steps you can take to help avoid these infections and the symptoms to watch out for.
Some people with ITP who have severe bleeding may need to have platelet transfusions and be hospitalized. Some will need a platelet transfusion before having surgery. For a platelet transfusion, donor platelets from a blood bank are injected into the recipient's bloodstream to increase the platelet count for a short time.
Some types of infections can briefly lower a person's platelet count. If a person with ITP has an infection that can lower the number of platelets, treating the infection may help raise the platelet count and reduce bleeding problems.
If a person who has ITP is taking medicine that can lower the number of platelets or cause bleeding, stopping the medicine can sometimes help raise the platelet count or prevent bleeding. For example, aspirin and ibuprofen are common medicines that reduce platelet function and increase the chance of bleeding. If you have ITP, you shouldn't use these medicines.
You can't prevent idiopathic thrombocytopenic purpura from occurring, but you can prevent its complications.
Living with idiopathic thrombocytopenic purpura
If you have idiopathic thrombocytopenic purpura (ITP):
Idiopathic thrombocytopenic purpura in pregnancy
In women who are pregnant and have ITP, the ITP usually doesn't affect the baby. However, some babies born to mothers with ITP are born with or develop low numbers of platelets soon after birth. Their platelets almost always return to normal without any treatment. Treatment can speed the recovery in the few babies whose platelet counts are very low.
Treatment for ITP during pregnancy depends on the woman's platelet count. If treatment is needed, the doctor will take a close look at the possible effects of the treatment on the unborn baby.
Women who have milder cases of ITP can usually go through pregnancy without treatment. Pregnant women with very low platelet counts or a lot of bleeding are more likely to have serious heavy bleeding during delivery or afterward. To prevent serious bleeding, these women are usually treated.