Aethritis and arthralgia in infection with Mycoplasma pneumoniae.

Mycoplasma pneumoniae, first identified as the cause of Eaton agent pneumonia in 1962 by Chanock, Hayflick, and Barile, remains the only species of mycoplasma proven to be a human pathogen (Griffin and Crawford, 1969). It attacks mainly the respiratory system but is also a recognized cause of acute haemolytic anaemia (Peterson, Ham, and Finland, 1943) and erythema multiforme (Gordon and Lyell, 1969). Involvement of the ear, heart and central nervous system has also been described (Lambert, 1 968a), and recently three cases with joint involvement have been reported (Lambert, 1968b). A further four cases are now presented.