Haemolytic anaemia due to cold agglutinins caused by psittacosis

A 69-yr-old previously healthy woman, presenting with jaundice and the clinical symptoms of an atypical pneumonia, was hospitalized. Haemolytic anaemia due to cold agglutinins was diagnosed, and erythromycin therapy for a suspected Mycoplasma pneumoniae infection was instituted. Serological testing revealed, however, that the infection was attributable to Chlamydia psittaci. The literature on psittacosis and haematological complications is reviewed. Cold agglutinins are sometimes found in association with psittacosis, but a concomitant haemolytic anaemia is rare.