When Cold Meets Hemolysis: A Unique Case of Paroxysmal Cold Hemoglobinuria in an Adult

Paroxysmal cold hemoglobinuria (PCH) is a rare autoimmune hemolytic anemia, historically linked to syphilis and mainly seen in children. We report a case in a young adult during fall, following a recent upper respiratory infection. Common infectious triggers were ruled out and imaging showed no masses. The patient presented with severe anemia (hemoglobin level, 3.6 g/dL) and received steroids, 2 rituximab infusions, and 9 units of packed red blood cells. His symptoms improved and he was discharged after 12 days on oral steroids with stable hemoglobin. This case highlights the importance of recognizing atypical adult presentations of PCH.