Severe hemolytic anemia and excessive leukocytosis masking mycoplasma pneumonia

The formation of cold agglutinins is frequently observed during Mycoplasma pneumoniae infections. Nevertheless. severe hemolysis is exceptional. We re port a case of life-threatening hemolytic anemia caused by M. pneumoniae. A s the leucocyte count was excessively elevated, the differential diagnosis primarily comprised hematological malignancies, The presence of cold agglut inins indicated the correct diagnosis, which was confirmed by highly elevat ed levels of both IgG and IgM antibodies to M. pneumoniae and a chest X-ray suggestive of atypical pneumonia. The patient was treated with roxithromyc in and showed a favorable recovery within ten days after admission. This ca se demonstrates that, even in patients with clinically mild pneumonia, M, p neumoniae may be the cause of severe anemia.