Atypical pneumonia

Alternative Names

Walking pneumonia; Chlamydophila pneumoniae; Community-acquired pneumonia – atypical

Definition of Atypical pneumonia

Atypical pneumonia refers to pneumonia caused by certain bacteria, including , , and .

Causes, incidence, and risk factors

Mycoplasma pneumonia is a type of atypical pneumonia. It is caused by the bacteria . It typically affects people younger than age 40. For more information on this type of pneumonia, see: Mycoplasma pneumonia


Pneumonia due to mycoplasma and chlamydophila bacteria is usually mild.

Signs and tests

Persons with suspected pneumonia should have a complete medical evaluation. It may be hard for your health care provider to tell whether you have pneumonia or bronchitis, so you may need a . Depending on the severity of the illness, other tests may be done, including:


Take these steps at home:

Expectations (prognosis)

Most patients with pneumonia due to mycoplasma or chlamydophila do well with the right antibiotic therapy. can be severe, leading to problems such as kidney failure, diabetes, , a weak immune system, and death.


Denis Hadjiliadis, MD, Assistant Professor of Medicine, Division of Pulmonary, Allergy and Critical Care, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 9/15/2010

Respiratory system

ADAM Medical Encyclopedia

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