Digital Ulcers in an 11-Year-Old Boy: An Unusual Presentation of Protein S Deficiency

Abstract

Protein S deficiency is characterized by decreased activity of Protein S, a serine protease complex with role in coagulation, apoptosis and inflammation. Protein S deficiency can be congenital or acquired. Protein S deficiency can be due to multiple causes including Vitamin K antagonists, hepatic diseases, SLE, myeloproliferative disorder and DIC. It commonly presents as venous thrombotic events such as deep venous thrombosis and pulmonary embolism. We present a case of an 11-year-old boy who presented to the OPD of tertiary care hospital with a two-month history of multiple painful erosions and ulcers on both feet, predominantly involving toes. He had previously lost the distal phalanx of the third toe following a similar episode one year earlier. Extensive laboratory investigations revealed decreased levels of protein S, thereby confirming the diagnosis. This case highlights an unusual presentation ‘digital ulcers’ in a pediatric patient with underlying Protein S deficiency. This underscores the importance of considering coagulation disorders in the differential diagnosis of recurrent ulcers in young patients.