Severe Warm Autoimmune Hemolytic Anemia in a 7-Month-Old Infant Associated With a Mycoplasma Pneumoniae Infection.

A 7-month-old female infant had clinical and laboratory evidence of severe warm autoimmune hemolytic anemia. She also had clinical evidence of an upper respiratory tract infection with molecular detection of Mycoplasma pneumoniae. Although reticulocytopenic initially, she responded to red blood cell transfusion, steroids, and intravenous immunoglobulin and remains well today. With the increasing use of multiplex respiratory viral and bacterial pathogen detection systems, the rare association described in this report may prove to be more common than previously thought and may provide insight into the pathogenesis and clinical consequences of red blood cell autoantibodies.