Platelet function defect (1464)

Key points below

Blood vessels carry blood through the body. When you are injured, blood vessels may be damaged.  This can cause blood to leak through holes in the wall of the blood vessel. Normally, these things happen to stop the bleeding:

1. Small cells in the blood shaped like plates (called platelets) gather at the wound.
2. These platelets stick together to make a plug. 
3. A clot that is like mesh forms to help the platelet plug stay in place.
A platelet function defect means that one or more of these steps does not happen.

What is a platelet function defect?

There are different types of platelet function defects (PFD). The number of platelets is usually normal, but they don’t function like they should.

Mild hereditary type. The most common type that does not normally go away. 
Acquired PFDs. Some are caused by a medical condition. Others can be caused by medicines like:
Aspirin, ibuprofen, and naproxen.
Blood thinners.
Some antibiotics, antidepressants, anti-seizure medicines and heart drugs. 
Platelet function returns to normal when these medicines are stopped. 

What are the symptoms?

Symptoms can vary even in families with the same platelet function defect. Most people have mild symptoms. Some have no symptoms unless they are badly injured or have surgery. In a few people, this defect can cause severe bleeding. Symptoms may include:
Appear with little or no known injury. 
Show up on more than one part of the body.
Are 2 inches or larger. 
Have firm or tender bumps (called hematomas) in the center. 
Nosebleeds more than once a year that bleed heavily or take more than 10 minutes to stop even with pressure.
Bleeding that lasts a long time or is not normal after an injury, surgery, childbirth, or dental work.
Needing blood transfusions. 
The need to change tampons or pads every 1 to 2 hours during your period or using more than 24 tampons or pads a month.
Periods that last for more than a week. 
Missing work or school because of heavy blood flow during periods.

How is it diagnosed?

A detailed personal and family history, a physical exam and blood tests will be done. Blood tests include: 
Complete blood count. This test checks if there are enough platelets in the blood (platelet count) for the blood to clot as it should. 
PT and PTT tests.  These tests are done to see how long it takes blood to clot. This is called the clotting time.
Platelet clotting (aggregation) study. Platelets from a blood sample are stirred in tubes and watched for clumping. Substances are added to help platelets clump. If platelets do not clump during this test, there may be problems with how platelets release or clump. 

How is it treated?

Treatment depends on the type of PFD, as well as where and how bad the bleeding is. Most patients do not need treatment regularly. They do need treatment if they have surgery, dental work, or an injury. 
IV desmopression (DDAVP®). This medicine is injected into a vein before surgery or after an accident to prevent or decrease severe bleeding. The response to DDAVP varies. The hematologist may do a trial dose to see how your child responds to the medicine. Patients who do not respond to DDAVP may need a platelet transfusion if bleeding occurs. Side effects of DDAVP may include headache and redness in the face. DDAVP causes the body to hold on to fluid. Your child’s fluid intake will be watched carefully after using DDAVP to avoid too much fluid. 
Platelet transfusion. Treatment with platelets for bleeding or before surgery may be needed. 
Amicar or tranexamic acid (Lysteda.) These medicines are used alone or along with DDAVP to treat mouth bleeding and some nosebleeds. Sometimes, they can also be used to treat heavy periods.  They work to stabilize the blood clot in the mouth or nose. This lets the area heal and helps prevent it from bleeding again. The doctor will tell you how to use these medicines.  
Ointment. For frequent nosebleeds, put Vaseline® on the nasal passages to help keep nasal tissues moist. Saline gel may also help. 
Birth control pills. Birth control pills may help control heavy bleeding for women. 
Things to remember
Do not give your child aspirin or ibuprofen. Be sure to read medicine labels. Ask your pharmacist if you are not sure about a product. This includes herbal products.
Good dental care and regular visits to the dentist can decrease the need for dental surgery.
Have your child carry an ID to let medical personnel know about your child’s bleeding disorder.
Make sure your child always wears a helmet when biking, skating, or doing any activity where there is a risk of head injury.


Call your child’s doctor, nurse, or clinic if you have any questions or concerns or if your child:

  • Has had a serious accident or injury. Call 9-1-1 for emergency care first if needed.
  • Is having surgery or dental work, such as having a tooth pulled. Always call before the procedure.  Your child may need treatment to prevent or control bleeding before and after the procedure.
  • If your child has gums that bleed with flossing.
  • If your child has nosebleeds that are hard to control or occur very often.
  • If your child has other bleeding such as mouth bleeding or cuts that seems to last a long time. 
  • If bleeding with periods lasts more than 7 days or requires a change of protection more often than every 2 to 3 hours.
  • Has special health care needs not covered by this information.