Clinical Practice and Cases in Emergency Medicine

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 PCR (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 in returning travelers. Early diagnosis, targeted testing, and awareness of macrolide resistance are critical for timely intervention and improved outcomes.