Differential Diagnosis for Gum Bleeding with Normal Platelets, High PT, and Normal PTT

• Single most likely diagnosis:
  • Factor VII deficiency: This is the most likely diagnosis because Factor VII has the shortest half-life among the clotting factors and is the first to be affected in cases of vitamin K deficiency or liver disease, leading to an isolated prolongation of PT with normal PTT and platelet count.
• Other Likely diagnoses:
  • Vitamin K deficiency: Vitamin K is essential for the production of clotting factors, including Factor VII. A deficiency could lead to elevated PT levels.
  • Liver disease: The liver produces most of the clotting factors, including Factor VII. Liver dysfunction can lead to coagulopathy, with Factor VII being affected early, causing an isolated elevation of PT.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Warfarin therapy: Although the patient is not mentioned to be on anticoagulation, warfarin (a vitamin K antagonist) can cause an elevated PT by inhibiting the production of vitamin K-dependent clotting factors, starting with Factor VII.
  • Disseminated Intravascular Coagulation (DIC): Early stages of DIC can present with isolated prolongation of PT due to consumption of clotting factors, although this typically progresses to involve other parameters as well.
• Rare diagnoses:
  • Factor VII inhibitors: Autoantibodies against Factor VII are rare and can cause an isolated prolongation of PT.
  • Congenital Factor VII deficiency: A rare bleeding disorder characterized by a deficiency of Factor VII, which can present with bleeding symptoms and isolated PT prolongation.