What is Essential Thrombocytosis?

Essential thrombocytosis (ET), also known as primary or essential thrombocythemia, is a rare blood disorder that occurs when the blood contains an excessive number of platelets. This condition can lead to problems with bleeding and clotting. ET mainly affects adults between the ages of 50 and 70, though it can occasionally affect people under 40, especially women. ET is treatable and is generally a benign disorder, although serious complications can occur.

Having a high number of megakaryocyte cells in bone marrow is known to result in the overproduction of platelets in the blood. Gene mutations also have been linked to the disorder in roughly half of those who have it. Still, the exact cause of essential thrombocytosis has not been determined as of 2010.

Initial signs of ET usually include a blood clot and physical symptoms related to the clot’s location. A clot in the brain can cause dizziness, headaches, fainting and temporary problems with vision. Clots in the hands or feet can cause ulcers, tingling, numbness, redness or a burning sensation.

Signs of ET related to bleeding problems include bruising easily, bleeding gums, blood in the stool and nosebleeds. These symptoms are not as common as clotting symptoms. They only occur if the platelet count reaches more than 1 million platelets per microliter of blood.

Doctors use several tests to diagnose essential thrombocytosis. These include a complete blood count to check the number of platelets, genetic tests to look for gene mutations that could contribute to ET, and a blood smear to check for platelet abnormalities. Bone marrow tests are done when underlying conditions that could cause a high platelet count have been ruled out.

Many cases of ET in people younger than 60 only require occasional checkups. Medications that help lower platelet counts, such as low-dose aspirin and hydroxyurea, are the most common forms of treatment for those over 60 who have had blood clots. Other medications for ET include anagrelide and interferon alfa-2B.

In life-threatening cases of ET, plateletpheresis is performed. This procedure involves using an IV to move blood into a medical device that gets rid of platelets. The blood is then sent back through the IV to the body. This procedure provides a fast way to lower platelet levels, although the effect is temporary.

Essential thrombocytosis can also be managed at home by taking steps to decrease the chances of clotting or bleeding. Eating healthy foods, exercising, and giving up smoking lower the risk of developing conditions that can lead to clotting, such as high blood pressure, diabetes and high cholesterol. Being careful with sharp objects, switching to a soft-bristled toothbrush, and avoiding roughhousing with others can reduce the risk of bleeding.

Life expectancy with this blood disorder is normal in most cases. Complications such as miscarriage, preeclampsia, heart attacks and strokes can occur as a result of clotting problems, however. Severe hemorrhaging also can cause extreme blood loss, which can in rare cases lead to serious diseases such as acute leukemia.