Abstract
INTRODUCTION: Cold agglutinin hemolytic anemia is a rare but serious complication of infections, including Mycoplasma pneumoniae. This case highlights the importance of considering infectious causes in patients with unexplained hemolysis. CASE REPORT: A 62-year-old previously healthy male developed jaundice, dyspnea, and fatigue three weeks after returning from South America. Labs showed hemolysis with agglutination, a positive direct Coombs test, and elevated cold agglutinin titers. M pneumoniae was identified via polymerase chain reaction, confirming the diagnosis. He required uncrossmatched blood transfusion and was treated with doxycycline, with clinical improvement over four days. CONCLUSION: This case underscores the need for emergency physicians to recognize M pneumoniae-induced hemolysis during periods of increased incidence and seasonal activity. Early diagnosis, targeted testing, and awareness of macrolide resistance are critical for timely intervention and improved outcomes.