Atypical Pneumonia

Atypical Pneumonia in MRCP

Atypical pneumonia is a popular question in MRCP,a lot of candidates ask me why we call Legionella and Mycoplasma pneumonia, atypical pneumonia and why they are so important in exam? There are a few reasons,

1) These two types of pneumonia usually present with extra-pulmonary symptoms such as diarrhoe andvomitting.Besides that, they may lead to extra-pulmonary complications.
2) It is suprising common and may account up to 25% of total community acquired pneumonia. Click here to learn more about pneumonia!

A few important points to remember about these two types of pneumonia

1) Legionella pneumophilia is commonly found in cooling system ( air-conditioning system) and water carrying system.
2) Mycoplasma penumonia can cause haemolytic anemia ( cold agglutinin presents in 50%) and may lead to skin rash ( erythema multiforme)
3) Both can lead to a lot of extra-pulmonary complications such as myocarditis, pericarditis, pancraetitis, meningitis etc

Dignosis of a atypical penumonia

CXR may be non specific but remember for Legionella Pneumonia, diagnosis can be made with Legionella serology and urinary antigen test. For mycoplasma pneumonia, send for mycoplasma serology but cold agglutinin test may be helpful.

Treatment

Always remember that either macrolides or tetracycline can be used. However, add rifampicin in severe Legionella pneumonia