Walking pneumonia is also known as atypical pneumonia. It is known as atypical pneumonia as it is not a typical pneumonia as it is not caused by pathogens that usually cause the disease. Atypical pneumonia can be caused by a variety of microorganisms.
The term “atypical pneumonia” was introduced in the 1930s and contrasted with the most commonly known form of bacterial pneumonia caused by Streptococcus pneumoniae. Due to this distinction, it differentiates those likely to present with typical symptoms and atypical symptoms.
As briefly mentioned previously, the term “atypical pneumonia” is due to the fact that it is caused by organisms that do not commonly cause pneumonia. Atypical organisms can include bacteria, viruses, fungi, and protozoa. Atypical pneumonia also results in atypical symptoms. The term is sometimes contrasted (incorrectly) with viral and bacterial pneumonia.
Many organisms causing atypical pneumonia are unusual bacteria. For example, Chlamydias are intracellular bacteria while Mycoplasma does not have a cell wall. The identification of the responsible pathogen is important as various agents have different disease courses, progression, and respond to different treatments. It is known as walking pneumonia as most patients are well enough to still walk around and go on with their daily routines.