What's the difference between typical and atypical pneumonia?

Very little: "atypical" pneumomia is actually very common. "typical" pneumonia is caused by conventional bacteria, usually with a capsule. Most atypical pneumoia is caused by small organisms (mycoplasma, legionella) that infect the inside of the cell, as opposed to living outside the cell.

See below: Atypical pneumonia is pneumonia caused by mycoplasma, chlamydophilia and legionella species as opposed to usual bacterial pneumonia caused by other bacteria like streptococcus pneumoniae.

Mismatch of symptom: Patients presents with symptoms which do notmatch with clinical and radiological evidence of the peumonias i.e. Cocci , tband pcp.

Causing agents type: Typical pneumonia caused by typical organisms found in the resoiratory system such as strep pneumonia, staph aureus, klebsiella pneumonia, moraxella cataralis. And atypical pneumonia is cause by atypical organisms, but when one usually address it as such means mycoplasma pneumonia which is not a complete bacteria from microbiology point of view. Shahzeidi, md.