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Thrombocytopenia is a blood disorder that is caused by a low platelet count. The platelets are the cells in the blood that help blood to clot. Children with thrombocytopenia may have excessive bleeding, be easily bruised or develop a non-itchy rash.

What causes thrombocytopenia?

There are three major causes of thrombocytopenia:

  • Not enough platelets made in the bone marrow
  • An increased breakdown of platelets in the bloodstream
  • An increased breakdown of platelets in the spleen or liver

There can be many reasons why the bone marrow does not make enough platelets. Some of those include having:

  • Aplastic anemia
  • Cancer in the bone marrow, such as leukemia
  • Scarring of the liver (cirrhosis)
  • Folate deficiency
  • A rare infection in the bone marrow
  • Vitamin B12 deficiency

Breakdown of platelets in the bloodstream or liver can be caused by a variety of health conditions. Some of the more common are:

Sometimes drugs used to treat other illnesses can also cause a temporary breakdown of platelets.

What are the symptoms?

Your child may not have any symptoms at all, or may exhibit one or more of these more general symptoms:

  • Bleeding in the mouth or gums, especially when brushing teeth or biting into certain foods
  • Easy or unexplained bruising
  • Excessive nosebleeds
  • Unexplained, non-itchy rash (pinpoint red spots called petechia)

Testing and diagnosis

Testing and diagnostics will typically include:

  • A complete medical history of the child and family
  • A thorough physical exam
  • Complete blood count (CBC) – measures the number of red blood cells, white blood cells and the amount of hemoglobin in the blood. It also tells your doctor what fraction of your child's blood is composed of red blood cells, the average size of the red blood cells and the platelet count.
  • Blood clotting studies including a test (partial thromboplastin time or PTT) to determine how long it takes for the blood to clot and a prothrombin time times to measure the time it takes for the liquid part (plasma) of the blood to clot.

Additional tests may include:

Once the hematology and oncology team has diagnosed the cause and type of your child's thrombocytopenia, your pediatric specialist will provide a plan of care and treatment.


Because the hematology and oncology team at Cook Children's has extensive experience in the causes, diagnosis and treatment of thrombocytopenia, you can trust that your child will have access to the latest advancements in medical treatment including research and clinical trials. And because our focus is on kids and teens, a team that understands the importance of care when it comes to your child and your family.

We are here to help.

If your child has been diagnosed, you probably have lots of questions. We can help. If you would like to schedule an appointment, refer a patient or speak to our staff, please call our offices at 682-885-4007.