Abstract
We describe a case of cold agglutinin disease, secondary to Mycoplasma pneumoniae infection, which presented with anaemia and abdominal pains in apparent succession to a thoraco-abdominal trauma. An exploratory laparotomy, carried out because of suspected post-traumatic rupture of the spleen, was complicated by a transitory cardiorespiratory arrest. The subsequent and correct diagnosis of the mycoplasmal infection and the cold agglutinins led to specific and successful therapy. The previously unknown hypertrophic cardiomyopathy was a contributing factor to the cardiorespiratory arrest.