Von Willebrand disease

Overview

Board takeaway: Recognize mucosal bleeding and plan invasive care with hematology. The most common inherited bleeding disorder involves deficient or dysfunctional von Willebrand factor (vWF), impairing platelet adhesion and lowering factor VIII.

How does Von Willebrand disease affect dental management?

• Before invasive care: Consult hematology before invasive procedures; the type determines the plan
• DDAVP may be useful in responsive type 1 disease; confirm the hematology plan and response. It is ineffective in type 3 and generally contraindicated in type 2B because it can worsen thrombocytopenia.
• Factor support: vWF-containing factor concentrates for severe disease or DDAVP nonresponders
• Antifibrinolytics: Antifibrinolytics (tranexamic acid or aminocaproic acid) for mucosal procedures
• Local measures: atraumatic technique, sutures, gelatin sponge or oxidized cellulose, pressure
• Nerve blocks: ask hematology; infiltration and intraligamentary injections carry less risk
• Analgesia: Avoid aspirin and NSAIDs; use acetaminophen

Exam pearl

What is Von Willebrand disease?

An inherited bleeding disorder caused by a deficiency or defect of von Willebrand factor, the protein that helps platelets stick to injured vessel walls and carries clotting factor VIII.

What are the main systemic features of Von Willebrand disease?

• Inheritance: Usually autosomal dominant; affects both sexes. Hemophilia mainly affects males, but females can also be affected. CDC hemophilia overview.
• Type 1: partial quantitative deficiency; most common
• Type 2: qualitative defect; several subtypes
• Type 3: near-absent vWF; severe; recessive
• Bleeding pattern: Mucocutaneous bleeding: epistaxis, easy bruising, heavy menstrual bleeding, prolonged bleeding after surgery
• Routine labs: aPTT may be prolonged when factor VIII is low; PT and platelet count are usually normal, although type 2B can cause thrombocytopenia.
• Diagnostic limits: bleeding time and PFA-100 may be abnormal but cannot reliably establish or exclude vWD.
• Hematology tests: evaluate vWF antigen/activity and factor VIII. WFH diagnostic guidance.
• Recognition: Many mild cases are undiagnosed until a dental extraction or surgery

What oral findings occur in Von Willebrand disease?

• Gingival bleeding, especially with gingivitis
• Prolonged bleeding after exfoliation of primary teeth, extraction, or frenum injury
• Petechiae and ecchymoses of the oral mucosa

How do you tell Von Willebrand disease from hemophilia?

• vWD: predominantly mucocutaneous bleeding (gums, nose, skin); affects both sexes and is usually autosomal dominant.
• Hemophilia: predominantly deep bleeding into joints and muscles; X-linked and mainly affects males.
• Laboratory distinction: vWD involves platelet adhesion and may also prolong aPTT through low factor VIII. Bleeding time and PFA-100 are not reliable stand-alone diagnostic tests; hematology uses vWF studies and factor assays. WFH diagnostic guidance.

A 10-year-old girl bled for two days after a primary molar fell out. Her mother has heavy periods. What do you do?

• Suspect an inherited bleeding disorder, such as vWD. Take a family and bleeding history.
• Before elective invasive care: refer to the physician or hematologist for evaluation with CBC, PT, aPTT, and vWF studies.
• For active bleeding: apply pressure and local hemostatics, with sutures if needed.

For Von Willebrand disease, what is the role of desmopressin?

DDAVP releases stored von Willebrand factor and factor VIII. Use is based on a documented response, usually in type 1 vWD; it is not an automatic pre-extraction medicine.

• Ineffective: type 3.
• Generally contraindicated: type 2B, children under two years, seizure disorders, active cardiovascular disease, and type 1C vWD in the surgical setting.
• Hematology decision: selects therapy and confirms whether a prior response trial is needed.
• Prevent hyponatremia: follow prescribed fluid restriction and monitoring. Free-water retention can cause severe hyponatremia and seizures.

Match support to the procedure

• VWF concentrate and tranexamic acid may be needed.
• Tranexamic acid alone: the ASH/ISTH/NHF/WFH guideline conditionally supports this for selected type 1 patients with baseline VWF activity above 0.30 IU/mL, a mild bleeding phenotype, and a minor mucosal procedure.
• Evidence limit: certainty is very low; this is a hematology-directed option, not blanket clearance for every extraction.
• Regardless of systemic therapy: use local hemostasis and provide a delayed-bleeding plan.

Sources

• Supplemental hematology guideline: ASH/ISTH/NHF/WFH 2021 VWD management guideline: executive summary
• Definition: MedlinePlus Genetics: Von Willebrand disease
• Hematology Consultation for Pediatric Dental Patients
• Common Laboratory Values