American Medical Association Family Medical Guide - American Medical Association [372]
Children who have von Willebrand’s disease need to reduce their risk of injury by limiting or avoiding contact sports. Children who have the severe form of the disease may have to wear a protective helmet during most forms of physical activity.
If you know that you carry the gene for von Willebrand’s disease, or if you already have a child who has the disorder, seek genetic counseling (see page 952).
Thrombocytopenia
Thrombocytopenia results from the destruction or inadequate production of platelets (cell fragments that enable blood to clot). In thrombocytopenia, the blood contains too few platelets, causing prolonged bleeding when a person is injured.
Thrombocytopenia can have different causes. For example, it can result from taking some medications or from having radiation therapy (see page 23) or chemotherapy (see page 23) for cancer (which can inhibit the body’s production of platelets). People who have Hodgkin’s disease (see page 626) or lupus (see page 920) can develop thrombocytopenia from platelet destruction. Thrombocytopenia also can occur as a result of leukemia (see next page), when cancerous white blood cells crowd out platelet-forming blood cells.
Acute idiopathic thrombocytopenic purpura (ITP) usually occurs when, for unknown reasons, an immune system organ called the spleen forms antibodies (infection-fighting proteins) that mistakenly attack the platelets. In ITP, healthy platelets are damaged and removed from the bloodstream by the spleen at a high rate.
Dilutional thrombocytopenia can develop when a person has many blood transfusions in a short period of time, which can occur during surgery or when abnormal bleeding results from another blood disorder. In dilutional thrombocytopenia, the relative number of platelets in the blood can be reduced significantly.
Symptoms
The main symptom of thrombocytopenia is a rash of tiny bright red and dark red spots caused by bleeding in the skin. The rash can appear on any part of the body, but it often begins on the legs or wherever the skin has been irritated. A person can have frequent nosebleeds and a tendency to bruise easily. If a person’s platelet count is very low, prolonged external or internal bleeding can occur after an injury. See your doctor immediately if you develop a dark red rash or if you have any abnormal bleeding.
Diagnosis
If you have symptoms of thrombocytopenia, your doctor will ask about any medications you are taking and will order a blood test to measure the amount of platelets in your blood and to determine if the thrombocytopenia is a symptom of another disease. He or she may order an examination of a sample of your bone marrow under a microscope to evaluate its production of platelets.
Treatment
To treat thrombocytopenia, your doctor will probably ask you to stop taking all medications, because almost any drug can trigger the disease in susceptible people. If abnormal antibody production by the immune system is the cause, your doctor may prescribe a corticosteroid drug to reduce the production of the platelet-destroying antibodies, thereby increasing the number of platelets in your blood. The corticosteroids also reduce the abnormal destruction of platelets by the spleen. In many people, this treatment improves or clears up the disease within several weeks.
If treatment with corticosteroid drugs is not effective, a doctor may recommend a splenectomy, a surgical procedure to remove the spleen. Removing the spleen allows the platelets to circulate in the blood longer. If removing the spleen does not help, the doctor may recommend treatment with high-dose gamma globulin (the pooled antibodies of healthy donors) or immune-suppressing or chemotherapy drugs given intravenously (through a vein) over a few hours. All of these treatments suppress the immune system to keep it from producing the antibodies that destroy the platelets, thereby allowing the platelets to circulate longer.
If you have thrombocytopenia caused by abnormal