Cold haemagglutinin disease complicating Mycoplasma pneumoniae infection in a child under cytotoxic cancer treatment.

Acute cold haemagglutinin disease, most commonly associated with underlying mycoplasma infection, is rare in children. A 3-year-old girl who developed this auto-immune disease under intensive cytotoxic treatment for rhabdomyosarcoma is presented. Clinically, a livedo reticularis skin pattern upon exposure to cold which was reversible at room temperature and a spontaneous red cell agglutination of blood samples in vitro led to the diagnosis. Together with bronchopneumonia the girl developed hyper-IgM, high antibody titres against Mycoplasma pneumoniae, as well as high titres of cold agglutinins. Laboratory signs of mild intravascular haemolysis were found. Positive direct antiglobulin test resulted from coating of red cells with C3d and C4. Three different antibodies were identified in serum: nonspecific cold agglutinins without complement activation, anti-I specific cold agglutinins with complement activation, as well as a weak biphasic Donath-Landsteiner haemolysin. Under antibiotic treatment and a short course of predisolone the clinical course was mild.