von Willebrand Disease

Everyone has to deal with bruises and bloody noses from time to time. But excessive or prolonged bleeding can be a sign of a disorder known as von Willebrand disease.
For many people, the symptoms are so mild that they never even know they have the disorder. For those with more severe forms of the disease, though, getting the proper diagnosis and treatment usually makes them less likely to have problems.

What Is von Willebrand Disease?

Von Willebrand disease, or vWD, is an inherited disorder — meaning it's passed from parent to child through genes — that affects the blood's ability to clot properly. It takes its name from Dr. Erik von Willebrand, who first described the condition in 1926.
As a group, bleeding disorders (including one you might have heard about — hemophilia) are rare. Von Willebrand disease is the most common inherited bleeding disorder, affecting about 1% to 2% of people. Unlike hemophilia, which usually affects only guys, vWD affects both guys and girls.
Normally, bleeding usually occurs when a blood vessel is cut or torn. Platelets (small cells that float in the blood) plug the hole in the blood vessel to stop blood from leaking out. With the help of calcium, vitamin K, and a protein called fibrinogen, the platelets create a mesh to hold the plug in place and close the wound. As this mesh dries, it hardens and forms a scab to protect the wound as it heals.
A substance in the blood known as von Willebrand factor helps platelets stick to damaged blood vessels. Special proteins known as clotting factors are also needed to help blood clot. Von Willebrand factor carries one of these clotting factors, called factor VIII, in the blood.
People with von Willebrand disease have bleeding problems because the levels or function of these blood components needed for clotting are abnormal.

The Types of von Willebrand Disease

As with many conditions, there are various forms of vWD:

• In type 1, a person has less von Willebrand factor in the blood than normal. Although the condition can be made worse by taking aspirin and other nonsteroidal anti-inflammatory drugs (these drugs can block blood from clotting), the symptoms might be so mild that the person isn't ever diagnosed. People with type 1 vWD usually don't bleed spontaneously, but they can have significant bleeding with injuries, surgery, or when they have a tooth pulled. Type 1 is the most common and the mildest form of vWD.
• In type 2, the person's body makes von Willebrand factor that is abnormal, leading to bleeding problems.
• Type 3 patients have severe bleeding problems. The person has no measurable von Willebrand factor and very low factor VIII levels.
• In pseudo, or platelet-type, von Willebrand disease, the person's platelets are abnormal, making them stick to von Willebrand factor too well. This causes clotting problems due to low numbers of platelets and levels of von Willebrand factor.

What Causes It?

Like hemophilia, vWD is a genetic disorder that is passed from parent to child. The child of a man or a woman with vWD has a 50% chance of getting the gene for the condition. In types 1 and 2, a child has inherited the gene from one parent. In type 3, the child has inherited genes for the disease from both parents.

Signs and Symptoms

The symptoms of von Willebrand disease may include:

• bruising easily
• unusually heavy periods or other abnormal menstrual bleeding in girls
• bleeding from the gums, nose, and lining of the intestines
• prolonged oozing of blood from cuts or bleeding too much or for too long after a tooth is pulled or tonsils are removed

• Diagnosis and Treatment

  Because its symptoms can be mild, vWD can be difficult to diagnose. In addition to doing a physical examination, the doctor will ask you about any concerns and symptoms you have, your past health, your family's health, any medications you're taking, any allergies you may have, and other issues, such as bleeding problems in other family members. This is called the medical history.
  A number of lab tests may be done to diagnose the condition and to determine the specific type of von Willebrand disease the person has. These will include of von Willebrand factor antigen, von Willebrand activity (ristocetin cofactor), and factor VIII. Measuring von Willebrand multimers help to determine the type of von Willebrand disease. Sometimes tests need to be done more than once because a person's levels may change over time.
  For many teens with vWD, the condition doesn't require big lifestyle changes. Teens with more severe vWD should avoid unnecessary trauma, including contact sports like football and hockey, but other sports and activities are usually OK.
  If bleeding does occur, applying pressure to the area may be all that's needed. Someone who gets a nosebleed should put pressure on the bridge of the nose to help stop the bleeding.
  Girls with vWD who have started their periods might want to carry extra pads or even a change of clothes in case of accidents. Sometimes, the doctor may prescribe birth control pills to help control heavy menstrual bleeding.
  If these measures aren't enough to prevent or control bleeding problems, additional types of treatment may be needed. The most common treatment used for type 1 von Willebrand disease is the drug desmopressin, which causes a temporary increase in the von Willebrand factor level in the blood. It can be given by injection or intranasally (into the nose). Desmopressin may or may not be helpful for treating people with some forms of type 2 von Willebrand disease.
  People with type 3 (and some with type 2) disease require treatment with a medication, called Humate P, that contains both factor VIII and von Willebrand factor. This medication is given intravenously (injected into a vein). Patients with type 1 also might need Humate P in certain situations, such as after major trauma or major surgery, although they can generally be treated with desmopressin.
  Other treatments can include the use of a medication like Amicar to inhibit the breakdown of a clot.
  Reviewed by: Gregory C. Griffin, MD
  Date reviewed: May 2010