What is the most common cause of atypical pneumonia in children?

Mycoplasma pneumoniae is recognized as the most common cause of atypical pneumonia in children, particularly in those aged 5 years and older. This organism results in a type of pneumonia that often presents with a more gradual onset of symptoms compared to typical pneumonia caused by bacteria such as Streptococcus pneumoniae.

Clinical manifestations of Mycoplasma pneumoniae infection often include a dry cough, fever, malaise, and sometimes extrapulmonary symptoms such as a rash or aseptic meningitis. The diagnosis is generally supported by clinical history combined with serological tests or PCR, as traditional bacterial cultures are often inadequate for Mycoplasma infections.

In the context of pediatric atypical pneumonia, other organisms like Chlamydia pneumoniae can also be involved, but they are less common. While Streptococcus pneumoniae is a leading cause of typical pneumonia and can cause lobar pneumonia in children, it is not classified as an atypical pathogen. Legionella pneumophila is primarily associated with outbreaks in adults and is relatively rare in children. Therefore, Mycoplasma pneumoniae stands out as the most prevalent atypical pathogen responsible for pneumonia in children.