Differential Diagnosis for Easy Bruising

The patient's laboratory results show elevated factor VIII activity, von Willebrand factor antigen, and ristocetin cofactor, with a normal APTT and slightly elevated INR. Based on these results, the following differential diagnosis can be considered:

• Single Most Likely Diagnosis
  • Von Willebrand Disease (VWD): Although the von Willebrand factor antigen and ristocetin cofactor are elevated, VWD is still a possible diagnosis, as some types of VWD may have normal or elevated factor levels. The patient's easy bruising symptom is consistent with VWD.
• Other Likely Diagnoses
  • Hemophilia A Carrier: The elevated factor VIII activity could indicate that the patient is a carrier of hemophilia A. Carriers may have elevated factor VIII levels and experience easy bruising.
  • Von Willebrand Factor Elevating Conditions: Certain conditions, such as pregnancy, inflammation, or stress, can elevate von Willebrand factor levels. The patient's easy bruising could be related to an underlying condition that is causing elevated von Willebrand factor levels.
• Do Not Miss Diagnoses
  • Thrombotic Thrombocytopenic Purpura (TTP): Although the patient's platelet count is normal, TTP is a life-threatening condition that can cause easy bruising and thrombocytopenia. It is essential to consider TTP in the differential diagnosis, even if the platelet count is normal.
  • Disseminated Intravascular Coagulation (DIC): DIC is a condition that can cause easy bruising, thrombocytopenia, and coagulopathy. Although the patient's laboratory results do not show significant evidence of DIC, it is crucial to consider this diagnosis due to its potential severity.
• Rare Diagnoses
  • Factor VIII Inhibitor: The presence of a factor VIII inhibitor could cause easy bruising and elevated factor VIII activity. However, this condition is rare and typically occurs in patients with hemophilia A or other bleeding disorders.
  • Von Willebrand Factor Related Disorders: There are several rare disorders related to von Willebrand factor, such as von Willebrand factor deficiency or von Willebrand disease type 2N. These conditions can cause easy bruising and may be considered in the differential diagnosis if other more common conditions are ruled out.