A 7-week-old exclusively breastfed boy, born at home and given no postnatal injections, presents with sudden focal seizures and a bulging fontanelle. CT shows a large intracranial hemorrhage. Prothrombin time is markedly prolonged while aPTT, platelet count and fibrinogen are normal. What is the MOST likely diagnosis?
- A Hemophilia A
- B Neonatal disseminated intravascular coagulation
- C Late vitamin K deficiency bleeding ✓
- D Immune thrombocytopenia
Correct answer: C. Late vitamin K deficiency bleeding
Explanation
Classic late vitamin K deficiency bleeding occurs between 2 and 12 weeks in exclusively breastfed infants who did not receive prophylactic vitamin K at birth. Isolated prolongation of prothrombin time reflects deficiency of factors II, VII, IX and X. In hemophilia A the prothrombin time is normal because factor VIII lies in the intrinsic pathway, and DIC would prolong aPTT with thrombocytopenia and low fibrinogen.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.