My daughter was diagnosed with thrombosytosis. what causes this and how can it be treated?

Thrombocytosis: I'm sure by now you know that means too many platelets in the blood. Causes range from chronic infection or allergy to more serious problems with the bone marrow. What to do? Stop smoking as this is a common cause as well, avoid Ibuprofen like drugs as these can cause blood clots. Find the cause and treat that. Once treated, thrombocytosis will improve. A drug called Hydroxyurea is used.

depends: The most common cause of thrombocytosis (high platelet count) in children is what we call "reactive thrombocytosis." this is the body's normal reaction to recent infection and can last for weeks. She should be evaluated for underlying infections or other causes of inflammation and treating those will make the platelet count come back down. Other rare causes can be evaluated by her doctor.