Essential thrombocythemia is an uncommon disorder in which your body produces too many blood platelets. This condition may cause you to feel fatigued, lightheaded and to experience headaches and vision changes. It also increases your risk of blood clots.
Essential thrombocythemia is an uncommon disorder in which your body produces too many blood platelets. This condition may cause you to feel fatigued and lightheaded and to experience headaches and vision changes. It also increases your risk of blood clots.
Essential thrombocythemia (throm-boe-sie-THEE-me-uh) is more common in people over age 50, though younger people can develop it too. It’s somewhat more common in women.
Essential thrombocythemia is a chronic disease with no cure. If you have a mild form of the disease, you may not need treatment. If you have a severe condition, you may need medicine that lowers your platelet count, blood thinners or both.
Symptoms of Essential thrombocythemia
You may not have any noticeable symptoms of essential thrombocythemia. The first indication you have the disorder may be the development of a blood clot (thrombus). Clots can develop anywhere in your body, but with essential thrombocythemia they occur most often in your brain, hands and feet.
Signs and symptoms depend on where the clot forms. They include:
Dizziness or lightheadedness
Temporary vision changes
Numbness or tingling of the hands and feet
Redness, throbbing and burning pain in the hands and feet (erythromelalgia)
Less commonly, essential thrombocythemia may cause bleeding, especially if your platelet count is extremely high (more than 1 million platelets per microliter of blood). Bleeding may take the form of:
Bleeding from your mouth or gums
If a blood clot occurs in the arteries that supply the brain, it may cause a transient ischemic attack (TIA) or stroke. A TIA, or ministroke, is a temporary interruption of blood flow to part of the brain. Signs and symptoms of a stroke or TIA develop suddenly and include:
Weakness or numbness of your face, arm or leg, usually on one side of your body
Difficulty speaking or understanding speech (aphasia)>
Blurred, double or decreased vision
Causes of Essential thrombocythemia
Essential thrombocythemia is a type of chronic myeloproliferative disorder. That means the bone marrow, the spongy tissue inside your bones, makes too many of a certain type of cell. In the case of essential thrombocythemia, the bone marrow makes too many cells that create platelets.
It’s not clear what causes this to happen. About 90 percent of people with the disorder have an acquired gene mutation contributing to the disease.
Platelets stick together to help form blood clots. Normally, blood clots stop bleeding when you damage a blood vessel, such as when you get a cut.
A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. Someone with essential thrombocythemia has more than 450,000 platelets per microliter of blood.
Plus, the excess platelets may not function normally, leading to abnormal clotting or bleeding.
If an underlying condition such as an infection or iron deficiency causes a high platelet count, it’s called reactive, or secondary, thrombocythemia. Secondary thrombocythemia causes less risk of blood clots and bleeding than does essential thrombocythemia.
Complications of Essential thrombocythemia
Older people with essential thrombocythemia are at risk of complications. People who’ve had prior blood clots or bleeding problems related to the disease are also at risk of complications.
The abnormal blood clotting of essential thrombocythemia can lead to a variety of potentially serious complications, including:
Stroke.A clot that blocks blood flow to your brain can cause a stroke. If you develop signs and symptoms of a stroke, get immediate medical attention.
Heart attack. Blood clots that obstruct blood flow to your heart cause heart attacks. Get immediate attention if you develop signs and symptoms of a heart attack.
Excessive bleeding. This may appear as nosebleeds, bleeding gums or bruising.
Rarely, essential thrombocythemia may progress to these potentially life-threatening diseases:
Acute myelogenous leukemia.This is a type of white blood cell and bone marrow cancer that progresses rapidly.
Myelofibrosis.This progressive disorder results in bone marrow scarring, leading to severe anemia and enlargement of your liver and spleen.
Pregnant women with essential thrombocythemia have a higher risk of complications than women without the condition. But most women who have thrombocythemia have normal, healthy pregnancies.
However, uncontrolled thrombocythemia can lead to miscarriage and other complications. Your risk of complications may be reduced with regular checkups and medication, so be sure to have your doctor regularly monitor your condition.
Diagnosis of Essential thrombocythemia
If your blood count is above 450,000 platelets per microliter of blood, your doctor will look for an underlying condition. He or she will rule out all other causes of high platelet counts to confirm a diagnosis of essential thrombocythemia.
Samples of your blood will be checked for:
The number of platelets
The size of your platelets
The activity of your platelets
Specific genetic flaws, such as the JAK2, CALR or MPL gene mutation
Markers of inflammation
Bone marrow tests
Your doctor may also suggest two bone marrow tests:
Bone marrow aspiration.Your doctor extracts a small amount of your liquid bone marrow through a needle. The sample is examined under a microscope for abnormal cells.
Bone marrow biopsy. Your doctor takes a sample of solid bone marrow tissue through a needle. The sample is examined under a microscope to determine whether your bone marrow has a higher than normal number of the large cells that make platelets (megakaryocytes).
Although there’s no cure for essential thrombocythemia, there are treatments available. And, lifespan is expected to be normal despite the disease.
Treatment of essential thrombocythemia depends on your risk of blood-clotting or bleeding episodes. If you’re younger than 60 and have had no signs or symptoms, you may simply need periodic medical checkups.
Your doctor may prescribe medication if:
You’re older than 60 and have had previous blood clots or TIAs
You have cardiovascular risk factors, such as high cholesterol, high blood pressure and diabetes
Your doctor may suggest one of the following prescription drugs, perhaps along with low-dose aspirin, to reduce your platelet count or clotting risk:
Hydroxyurea (Droxia, Hydrea). This drug suppresses bone marrow production of blood cells, including platelets. Its side effects are usually mild, and may include nausea, hair loss, discolored nails and ulcers in the mouth or on the legs.
Your doctor will monitor your blood counts and liver function. There’s some concern that long-term use may slightly increase the risk of developing acute myelogenous leukemia.
Anagrelide (Agrylin).Unlike hydroxyurea, anagrelide isn’t associated with an increased risk of leukemia, but it’s not considered as effective. Side effects may include fluid retention, heart problems, headaches, dizziness, nausea and diarrhea.
Interferon alfa (Intron A) or peginterferon alpha-2a (Pegasys).This drug is given by injection, and may cause worse side effects than hydroxyurea or anagrelide does. But it’s the best choice for some people. Side effects may include flu-like symptoms, confusion, nausea, depression, diarrhea, seizures, irritability and sleepiness.