Von Willebrand disease, or VWD, is a genetic (inherited) bleeding disorder that
prevents blood from clotting properly. Bleeding disorders (including hemophilia)
are rare. Von Willebrand disease is the most common bleeding disorder, and affects
males and females equally.
What Happens in Von Willebrand Disease?
Normally, when a blood vessel is cut or torn, bleeding stops because of the blood's
ability to clot (to plug the hole in the blood vessel and stop the flow of blood).
This complex process involves platelets and proteins called clotting factors.
Von Willebrand factor is involved in the early stages of blood clotting, and also
carries the important clotting protein factor VIII. In people with VWD, the amount
of Von Willebrand factor clotting protein in the blood
is lower than normal or doesn't work as it should.
What Are the Signs & Symptoms of Von Willebrand Disease?
Many kids with VWD have such mild symptoms that they never know they have it. Those
with a more severe form of the disease, though, need proper diagnosis and a treatment
plan to help them reduce bleeding symptoms.
bleeding in the mucous membranes, such as the gums, nose, and lining of the gastrointestinal
What Are the Types of Von Willebrand Disease?
There are various forms of VWD:
In Type 1, the level of Von Willebrand factor in the blood is
reduced and the level of factor VIII also might be reduced. This is the most common
and mildest form of the disease. The symptoms might be so minor that the person isn't
ever diagnosed. People with type I VWD usually do not bleed spontaneously but can
have a lot of bleeding with menstrual periods, trauma, surgery, or when they have
a tooth pulled.
In Type 2, the level of Von Willebrand factor in the blood is
normal, but doesn't work as it should. Type 2 has several subtypes, including:
Type 2A: The building blocks that make up the factor (called
multimers) are smaller than usual or break down too easily.
Type 2B: The factor sticks to the platelets too well, leading
to clumping of the platelets, which can cause a low platelet number.
In Type 3, Von Willebrand factor and factor VIII levels are very
low or missing. Symptoms are severe and may include bleeding into joints and muscles.
Pseudo, or platelet-type, Von Willebrand disease
is similar to type 2B, but the defect is in the platelets instead of in the factor.
What Causes Von Willebrand Disease?
Like hemophilia, VWD is a genetic
disorder. Usually, it's passed from parent to child, but sometimes can happen after
birth. The child of a man or a woman with VWD has a 50% chance of getting the gene.
A child also can inherit the gene and show no symptoms, but still can pass the
gene on to any offspring.
How Is Von Willebrand Disease Diagnosed?
Because symptoms can be mild, VWD can be hard to diagnose and often isn't found.
Von Willebrand activity
test (also called ristocetin cofactor or RCF activity test), which measures how
well the Von Willebrand factor works
activity test (also called factor VIII coagulant assay), which measures the level
of factor VIII and how it's working
Von Willebrand multimers test, which helps to classify the type of Von Willebrand
platelet function tests, which see how well the platelets work
Tests might need to be repeated because the levels they detect may rise and fall
over time. Also, the doctor will take a family
to see if other relatives have a bleeding disorder.
How Is Von Willebrand Disease Treated?
The most common treatment for VWD is desmopressin. This synthetic
causes a temporary increase in the Von Willebrand factor and factor VIII levels. It
can be given as an injection or a nasal spray. But it doesn't work for everyone and
may not be helpful in treating type 2. Some patients will need treatment with an intravenous
(IV, given into a vein) form of Von Willebrand factor.
Medicine to slow or prevent the breakdown of blood clots also might be used, and
fibrin glue can be put directly on a wound to stop bleeding.
Treatments for girls with heavy menstrual bleeding from VWD also might include
birth control pills
or an IUD that contains
the hormone progestin.
What Else Should I Know?
If bleeding happens, apply pressure to the area.
pinch the soft part of the nose and have your child lean slightly forward to keep
the blood from flowing down the throat.
Tell your child's hematologist if any surgery or procedures are planned.
Male infants with a family history of VWD should not be circumcised
without a doctor's OK.
Girls with VWD who are having very heavy or long-lasting periods may want to see
an adolescent medicine doctor or a gynecologist for advice.
Tell the dentist that your child has VWD. Your child might need medicine before
dental work to reduce bleeding.
Kids with VWD should not take aspirin and other non-steroidal anti-inflammatory
drugs (NSAIDs), such as ibuprofen, for pain or fever. These drugs affect how platelets
work and can increase the risk of bleeding. It is safe to take acetaminophen,
which doesn't affect platelet function.
Contact sports might risky for kids and teens with VWD. Instead, they could stay
active with activities like swimming, biking, and walking. Discuss any restrictions
with your doctor.
Call your doctor right away if your child has any excessive or unexplained bleeding.