Protein S Deficiency with Recurrent Deep Vein Thrombosis and Post Thrombotic Syndrome: A Case Report

Protein S is a vitamin K-dependent protein that acts as a break in secondary hemostasis by inactivating activated factor V and activated factor VIII. We report a case of a 40 years old male who had the first episode of deep vein thrombosis of the left lower limb 10 years back, which despite treatment, reoccurred 3 months later in the bilateral lower limb. Thrombophilic screening showed severe protein S deficiency. The patient then developed deep vein thrombosis of both upper limbs. The patient was advised to place an inferior vena cava filter, which he denied. The patient is now presenting with multiple episodes of post-thrombotic syndrome. Such attacks are treated with elastic compression stockings, rivaroxaban, and morphine. However, despite medication, the pain has not yet subsided. Hence, even though protein S deficiency is the rare cause of deep vein thrombosis when recurrent should be considered despite its rare occurrence.