Mycoplasma Pneumonia Infection Complicated with Hemolytic Anemia and Persistent Leukocytosis in a Middle-Aged Woman: A Case- Report.

Background: Mycoplasma pneumonia is one of the causes of community-acquired pneumonia (CAD) with rare extrapulmonary complications, including hemolytic anemia, persistent leukocytosis, Stevens-Johnson syndrome, meningoencephalitis. While these conditions are most common in children and young adults, typically those aged 5 to 20 years, this case report covers Mycoplasma pneumonia with the very rare complication of hemolytic anemia and persistent leukocytosis in a middle-aged woman. Case Presentation: A 44-year-old woman with a history of high-grade fever for 10 days, fatigue, and headache came to the emergency medicine. Laboratory evaluation revealed severe normocytic anemia (Hb 5.3 g/dL), leukocytosis (42,000/μL), and thrombocytosis (564,000/μL). Cold agglutinin testing confirmed anti-I IgM–mediated disease with high titers (1:256), and serology was positive for M. pneumoniae IgM and IgG antibodies. She was treated with warmed red cell transfusions, intravenous methylprednisolone, and clarithromycin, followed by oral levofloxacin. Her condition improved significantly. Rationale: This case highlights the diagnostic complexity in a woman patient with rare hemolytic anemias in the context of atypical infections and the approach for their diagnosis and appropriate treatment. The coexistence of IgM-mediated autoimmune hemolytic anemia and leukocytosis poses diagnostic and therapeutic challenges that are relevant to clinical practice. This case underscores the diagnostic and therapeutic challenges of cold agglutinin hemolysis secondary to M. pneumoniae infection.