ITP is a blood disorder characterized by an abnormal decrease in the number of platelets in the blood. Platelets are cells in the blood that help stop bleeding. A decrease in platelets can result in easy bruising, bleeding gums, and internal bleeding.
ITP affects approximately four to eight per 100,000 children under the age of 15 each year in the US. There are two forms of ITP:
In most cases, the cause of ITP is unknown. It is not contagious, meaning a child cannot "catch it" from playing with another child with ITP. It is also important to know that nothing the parents, nor the child, did caused the disorder.
Often, the child may have had a virus or viral infection about three weeks before developing ITP. It is believed that the body, when making antibodies against a virus, "accidentally" also made an antibody that can stick to the platelet cells. The body recognizes any cells with antibodies as foreign cells and destroys them. That is why ITP is also referred to as immune thrombocytopenic purpura.
The bone marrow is the soft, spongy center of the long bones and is responsible for making blood cells, including platelets. The bone marrow responds to the low number of platelets and produces many more to send out to the body. A physician can look at the cells in the bone marrow and, in a child with ITP, would see many young platelets that have been produced. However, the blood test results of the circulating blood would show a very low number of platelets. The body is producing the cells normally, but the body is also destroying them. In most cases, other blood tests are normal except for the low number of platelets. ITP platelets usually survive only a few hours, in comparison to normal platelets which have a lifespan of 7 to 10 days.
Platelets are essential for the formation of a blood clot. Blood clots consist of a mass of fibers and blood cells. Platelets travel to a damaged area and stick together to form a plug, whenever a person is cut, for example. If there are not enough platelets, a clot cannot be formed, resulting in more bleeding.
There has been research involved in looking at certain medications causing ITP. Some medications may result in the altering of platelet function. At this time, no direct link has been made with any specific medication that may cause ITP.
Normal platelet count is in the range of 150,000 to 450,000. With ITP, the platelet count is less than 100,000. By the time significant bleeding occurs, the child may have a platelet count of less than 10,000. The lower the platelet count, the greater the risk of bleeding.
Because platelets help stop bleeding, the symptoms of ITP are related to increased bleeding. However, each child may experience symptoms differently. Symptoms may include:
The symptoms of ITP may resemble other blood disorders or medical problems. Always consult your child's physician for a diagnosis.
In addition to a complete medical history and physical examination, diagnostic procedures for ITP may include:
Sometimes, a bone marrow aspiration is performed to look at the production of platelets and to rule out any abnormal cells the marrow may be producing that could lower platelet counts.
Specific treatment for ITP will be determined by your child's physician based on:
Not all children with ITP require treatment. Close monitoring of your child's platelets and prevention of serious bleeding complications may be the course of action chosen until the body is able to correct the disorder on its own. Many children with ITP are able to spontaneously recover in about 2 to 4 days.
When treatment is necessary, the two most common forms of treatment are steroids and intravenous gamma globulin:
Other treatments for ITP may include:
The parents of a child with the disorder need to be aware of how to prevent injuries and bleeding. Consider the following:
It is important to discuss with your child's physician other limitations necessary to prevent injuries in a child with ITP.
Although there is no known cause of ITP and there is no cure, the prognosis for a child with ITP is very good.
Usually, the body stops making the antibodies that are attacking the platelets and the disorder resolves on its own. The goal of treatment is to keep the child's platelets in a safe range until the body corrects the problem.
Overall, prevention of serious bleeding, such as head injuries, is the most significant factor in prognosis. Providing a safe environment, prompt medical attention, and continued medical care are all indications for a long term, healthy prognosis.