What is polycythemia vera in children?

Polycythemia vera is a very rare blood disorder in children. With polycythemia vera, the bone marrow makes too many red blood cells. The extra cells make the blood too thick. This may lead to blood clots. The clots can decrease the blood supply to organs, tissues, and cells.

What causes polycythemia vera in a child?

Genetic mutations in bone marrow cells cause polycythemia vera. Some forms can be passed from parents to children. Some forms are not.

What are the symptoms of polycythemia vera in a child?

Some children do not have symptoms, and polycythemia vera may be found when they're having blood tests for other reasons. Symptoms occur more often in adults. 

Symptoms can occur a bit differently in each child. They can include:

• Headaches

• Dizziness

• Feeling weak and tired

• Trouble breathing

• Enlarged spleen

• Trouble seeing

• Itching or burning

• Reddish coloring of face

• Bleeding gums

• Losing weight

The symptoms of polycythemia can be like other health conditions. Make sure your child sees their healthcare provider for a diagnosis.

How is polycythemia vera diagnosed in a child?

The healthcare provider will ask about your child’s symptoms and health history. They will give your child a physical exam. Your child may also have tests, such as:

• Hemoglobin and hematocrit. This test measures the amount of hemoglobin and red blood cells in the blood.

• Complete blood count (CBC). A complete blood count checks the red blood cells, white blood cells, blood clotting cells (platelets), and, sometimes, young red blood cells (reticulocytes). It includes hemoglobin and hematocrit and more details about the red blood cells.

• Peripheral smear. A small sample of blood is examined under a microscope. Blood cells are checked to see if they look normal or not.

• Erythropoietin (EPO) level. This test measures the amount of EPO in the blood. EPO is a hormone that helps make red blood cells.

• Genetic tests. These tests look for gene mutations linked with polycythemia vera, such as JAK2, CALR, and MPL, in addition to mutations in the EPO receptor.

How is polycythemia vera treated in a child?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

Your child's healthcare provider should refer you to a hematologist, a specialist in blood disorders. Treatment may include:

• Venipuncture to remove some blood, which reduces the number of red blood cells (done like when a person donates blood)

• Low dose of aspirin to prevent blood clots

• Medicines to decrease the production of red blood cells in the bone marrow

• Other treatments that are being studied

What are possible complications of polycythemia vera in a child?

Complications depend on how severe the polycythemia is. They can include:

• Deep vein thromboses or blood clots in the veins

• Blood clots in the veins of the liver

• Heavy bleeding

• Stroke

• Leukemia

How can I help my child live with polycythemia vera?

Your child will be watched for changes in blood test results or signs and symptoms of complications. Talk with your child's blood specialist about whether your child needs to take special precautions or shouldn't do certain activities.

When should I call my child's healthcare provider?

Call your child's healthcare provider if you notice new or worse symptoms. For example, call if your child is more tired than usual. Call your child's healthcare provider or get medical care if your child:

• Is injured

• Has pain in their arms or legs or abdomen (this may be from a blood clot)

• Has any other new symptoms or behavior changes

Key points about polycythemia vera in children

• Polycythemia vera is a blood disorder in which the bone marrow produces too many red blood cells. The extra cells make the blood too thick, increasing the risk of blood clots.

• Blood clots may cause serious problems depending on where they form. The clots can decrease the blood supply to the heart, brain, or liver, for example.

• Treatment may include venipuncture to remove blood and taking aspirin.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.

• Before your visit, write down questions you want answered.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.

• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

• Ask if your child’s condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if your child does not take the medicine or have the test or procedure.

• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.