Severe mycoplasma pneumoniae pneumonia combined with cold agglutinin disease and pulmonary embolism in childhood: A case report and review of the literature.

This was a case report and literature review, aimed to strengthen the understanding and therapy of mycoplasma pneumoniae (MP) pneumonia combined with cold agglutinin disease and pulmonary embolism in children. A 7-year-old boy was taken to the hospital with fever for 7 days, cough for 5 days, and recurrent cyanosis at the extremities of one day duration. Pulmonary artery computed tomography angiography (CTA) showed pulmonary embolism, double pneumonia, and pleural effusion. Mycoplasma (MP) antibody IgM, Coombs test, and anti C3d were positive while anti-IgG was negative. After treatment, the patient improved. One month after discharge, the Coombs test was negative, and pulmonary CTA showed no pulmonary embolism. The diagnosis was severe MP with cold agglutinin disease and pulmonary embolism. The cases were reviewed, involving a total of 18 cases. Two patients had pulmonary embolism, and one had Raynaud's phenomenon with superior mesenteric artery and popliteal artery embolism. After treatment, 16 cases recovered while two cases were lost to follow up. We conclude that although the disease may be associated with severe complications such as embolism, acrocyanosis, and gangrene, the prognosis is relatively good for most patients.