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Mycoplasma pneumoniae infection

Evidence last reviewed: 13 Apr 2026
Topic last updated: 07 May 2026

Summary

Definition

History and exam

Key diagnostic factors

  • persistent cough
  • dry cough
  • prolonged symptoms
  • fever
  • adventitious sounds on physical exam
Full details

Other diagnostic factors

  • throat involvement
  • rash
  • headache
  • hepatitis
Full details

Risk factors

  • close community settings
  • exposure to a person with respiratory tract infection
  • cigarette smoking
  • age <30 years
  • immunosuppression
  • asplenia
Full details

Diagnostic tests

1st tests to order

  • CBC
  • hemoglobin
  • LFTs
  • pulse oximetry
  • BUN and electrolytes
  • C-reactive protein
  • chest x-ray
Full details

Tests to consider

  • nucleic acid amplification test (NAAT)
  • serology
  • culture ± Gram stain
  • antigen test
Full details

Emerging tests

  • point of care ultrasound, lung

Treatment algorithm

ACUTE

with pneumonia

Contributors

Authors

Lorenzo Dr Francesco, MD, SFHM, FACP

Professor of Medicine

Department of Medicine

Division of General Internal Medicine

Emory University School of Medicine

Atlanta, GA

Disclosures

LDF declares that he has no competing interests.

Takeshi Saraya, MD, PhD

Professor

Department of Respiratory Medicine

Kyorin University School of Medicine

Tokyo

Japan

Disclosures

TS declares that he has no competing interests.

Acknowledgements

Dr Di Francesco and Dr Takeshi Saraya would like to gratefully acknowledge Dr Ran Nir-Paz, a previous contributor to this topic. RNP declares no competing interests.

Peer reviewers

Enno Jacobs, MD

Director

Institute for Medical Microbiology and Hygiene

Dresden

Germany

Disclosures

EJ declares that he has no competing interests.

Laura J. Christie, MD

Research Scientist

Pediatric Infectious Disease

California Department of Public Health

Viral and Rickettsial Disease Laboratory

Richmond

CA

Disclosures

LC declares that she has no competing interests.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

British Thoracic Society. BTS guidelines for the management of community acquired pneumonia in adults: update 2009. Jan 2015 [internet publication].Full text

Metlay JP, Waterer GW, Long AC, et al. Diagnosis and treatment of adults with community-acquired pneumonia. An official clinical practice guideline of the American Thoracic Society and Infectious Diseases Society of America. Am J Respir Crit Care Med. 2019 Oct 1;200(7):e45-67.Full text  Abstract

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.
  • Mycoplasma pneumoniae infection images
  • Differentials

    • Coronavirus disease 2019 (COVID-19)
    • Typical bacterial pneumonia
    • Viral pneumonia
    More Differentials
  • Guidelines

    • Diagnosis and management of community-acquired pneumonia: an official American Thoracic Society clinical practice guideline
    • The JRS guidelines for the management of pneumonia in adults 2024
    More Guidelines
  • Patient information

    Pneumonia

    Pneumonia: do I need a vaccine?

    More Patient information
  • Calculators

    CURB-65 pneumonia severity score

    Community-acquired pneumonia severity index (PSI) for adults

    More Calculators
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