Mycoplasma pneumoniae and Chlamydia pneumoniae cause lower respiratory tract disease in paediatric patients.

New studies suggest that Mycoplasma pneumoniae and Chlamydia pneumoniae play a more significant role as causes of lower respiratory tract infections in childhood than was previously thought. In particular, the incidence of infections caused by these pathogens is high in children aged less than 5 years, the infections themselves seem to be a possible cause of wheezing, and may present a more complicated course when not treated with adequate antimicrobial agents. However, despite the increasing pathogenic significance of M. pneumoniae and C. pneumoniae, progress in fighting them is hampered by the lack of rapid and standardized diagnostic methods. This not only makes it practically impossible for practitioners to make a specific microbiological diagnosis, but has also had an adverse effect on treatment trials and has generated some questionable results. Carefully randomized and controlled trials are clearly needed to examine the effectiveness of different antibiotics against M. pneumoniae or C. pneumoniae and the optimal duration of therapy in various patient populations.