There are over 30 microorganisms that can cause pneumonia, the most common being the Streptococcus pneumoniae bacteria, the influenza virus, and the respiratory syncytial virus (RSV). A pneumonia infection caused by one of these microorganisms will not cause asthma.
Another common cause of pneumonia is the Mycoplasma pneumoniae bacteria. Pneumonia resulting from an infection caused by this bacterium is generally less severe, and is commonly referred to as “walking pneumonia.†Over the past few years, scientists have been studying the link between Mycoplasma infection and asthma.
Researchers have found that the Mycoplasma pneumoniae bacteria can linger for months after a patient recovers from pneumonia. This ongoing infection, even without noticeable symptoms, can force the immune system into overdrive, resulting in the chronic inflammation that is associated with asthma.
A study by researchers at UT Southwestern Medical Centers in Dallas has shown lab mice infected with Mycoplasma pneumoniae developing bronchial constriction, the cause of asthma attacks, as much as 18 months after infection. Laboratory cultures also show levels of Mycoplasma pneumonia to be higher in patients with asthma than in those without. Studies are now being undertaken to show whether or not antibiotic treatment is helpful in asthma cases where Mycoplasma pneumonia is present.