Hemorrhagic Pleural Effusion: A Rare Presentation of Vitamin K Deficiency in an Adult Patient.

Nutritionally acquired vitamin K deficiency is a rare condition in adults and can uncommonly present as hemorrhagic pleural effusion. We discuss the case of A 44-year-old apparently healthy man who presented with left-sided pleuritic chest pain two months after experiencing upper respiratory tract symptoms. Imaging revealed a loculated left-sided effusion, and a corresponding thoracentesis yielded exudative hemorrhagic fluid with no microbial growth. Laboratory work-up showed prolonged clotting time with low factors II, VII, and X activity, absence of clotting factor inhibitors, and very low serum vitamin K levels. A five-day course of oral vitamin K and nutritional optimization normalized the clotting profile. Acquired vitamin K deficiency from poor micronutrient intake is rare in adults and can result in hemorrhagic pleural effusion. Vitamin K supplementation can normalize the clotting profile while nutritional counseling helps prevent a recurrence. Malnutrition-induced vitamin K deficiency can occur in the setting of a major depressive disorder in adults. Thorough patient history and physical examination are necessary to promptly identify and reverse the coagulopathy.