Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease affecting platelets. Many people have no symptoms. If symptoms occur they can range from mild bruising to severe bleeding. In children the condition usually goes away in 6-8 weeks, without any treatment. In adults it is usually a lifelong condition. Treatment may or may not be necessary and may include steroids, immunoglobulin and surgery.
Understanding plateletsPlatelets are tiny components of the blood which help blood to clot when we injure ourselves. They are also known as thrombocytes. They are made inside bone, in the bone marrow. They are released into the bloodstream and travel through the body for about seven days, before they are removed by the spleen. The spleen is an organ that lies at the top of the abdomen under the ribs on the left-hand side.
What is idiopathic thrombocytopenic purpura?Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease involving platelets. In autoimmune disorders your body makes an antibody that damages another part of your body. In ITP the antibodies are made against platelets. Once the antibodies have attached to platelets, the platelets do not work so well. They are also removed more quickly by the spleen because they are abnormal.
- Idiopathic means that there is no known underlying cause found.
- Thrombocytopenic means not enough platelets.
- Purpura is a purple-red rash.
IDIOPATHIC THROMBOCYTOPENIC PURPURA IN CHILDREN
How common is it in children?ITP occurs in about 5 in 100,000 children. Girls are three times more likely to have it than boys.
What are the symptoms?
- Most children will not have any symptoms.
- Those who do develop symptoms have bruising and the rash - purpura. Some have bleeding such as nosebleeds. It usually appears over 1-2 days. The condition often occurs about 2-3 weeks after an infection (often a common viral infection). Occasionally, it follows immunisation. The symptoms disappear over 6-8 weeks in most cases.
- Very occasionally, it causes severe bleeding which requires emergency treatment.
- The platelet levels in about 1 in 10 affected children do not ever return to normal, which means that they have developed chronic (persistent) ITP.
How is it diagnosed?ITP is diagnosed by a blood test called a full blood count. This test shows that there are fewer platelets than normal. The laboratory will also have a look at the blood under a microscope.
Sometimes different tests will be needed to make sure that the low number of platelets is not due to another of the potential causes. Rarely, this involves taking a sample of bone marrow.
What is the treatment?Most children will not need treatment, even if the number of platelets is very low. The decision to treat is usually based on whether your child has serious bleeding or very pronounced bruising and purpura. If the symptoms are mild, usually there will be no need for treatment. Your child will need to have the full blood count repeated on a few occasions to check that the platelet numbers are stable and that the rest of the blood cell counts are remaining normal. If your child has bleeding and more severe bruising or purpura, treatment may be considered. The aim of treatment is to improve symptoms and increase the number of platelets.
If treatment is needed then the decision on what treatment to use can be difficult. This is because there have not been many studies testing the treatments against each other. The options for treatment include:
- Prednisolone. This is often the first type of treatment tried. It is a steroid medication and is taken as syrup or tablets. This may be given as a high dose over a short period of time (four days) or as a lower dose for a longer time (two weeks). Prednisolone has been shown to increase the number of platelets quickly in about 3 in 4 children with ITP.
- Other steroid options. High-dose methylprednisolone or high-dose dexamethasone. These are other types of steroid medicines that have also been shown to be effective in differing degrees. Dexamethasone is not often used in children.
- Intravenous immunoglobulin (IVIg). This is an injection of a protein into the bloodstream and has been shown to work well in about 8 in 10 children in increasing the number of platelets. It is not usually used as the first option because it involves an injection. It can also cause quite a lot of side-effects and is quite expensive. It may be used as an emergency treatment if your child has severe bleeding or needs surgery.
- Anti-D immunoglobulin. This is another type of protein that is also effective and causes fewer side-effects than IVIg. It can only be given to children whose blood group is RhD positive.
- Platelet transfusions. In a life threatening situation your child may be given a transfusion of platelets at the same time as being treated with steroids and IVIg. This only helps to increase the number of platelets for a short time. The transfused platelets are also attacked by the antibody that the body has produced and are destroyed by the spleen.
- Other medicines. A number of other medicines are being trialled. These are not routinely recommended, as not enough information is known yet about their use and side-effects.
- Surgery to remove the spleen (splenectomy). This is very rarely done in children with ITP. It is only really considered as an option if your child has life- threatening bleeding or severe chronic disease that is affecting their day-to-day functioning.