Two separated thrombi in deep veins associated with pulmonary embolism after Mycoplasma pneumoniae infection: a case in adolescent female

Mycoplasma pneumoniae is a common pathogen for respiratory infection in children, and vascular complication is one of the rarest extrapulmonary complications but with serious consequences. We report a twelve-year-old Chinese female presenting with fever, dry cough, and chest pain aggravated by respiration. She was diagnosed pneumonia due to Mycoplasma pneumoniae and treated with Azithromycin until unexpected tachypnea and swelling in the right lower limb happened. Then ultrasonic examination had revealed two separated thrombi in deep veins before pulmonary embolism was found. Finally she was cured by anticoagulation and immunosuppressive therapy. Though the mechanism of thrombosis after Mycoplasma pneumoniae infection remains unknown, the positive finding in anticardiolipin antibody as well as multi-site thromboses gives a strong hint to immune modulation. Thrombosis should be considered for those who have significantly increased C-reactive protein and positive anticardiolipin antibody after Mycoplasma pneumoniae infection. To our knowledge, this is the first report describing two unattached thrombi in deep veins associated with pulmonary embolism after Mycoplasma pneumonia infection.