Community-Acquired Pneumonia in Adults: Diagnosis and Management


Am Fam Physician. 2016 Nov 1;94(9):698-706.

Author disclosure: No relevant financial affiliations.

Community-acquired pneumonia is a leading cause of death. Risk factors include older age and medical comorbidities. Diagnosis is suggested by a history of cough, dyspnea, pleuritic pain, or acute functional or cognitive decline, with abnormal vital signs (e.g., fever, tachycardia) and lung examination findings. Diagnosis should be confirmed by chest radiography or ultrasonography. Validated prediction scores for pneumonia severity can guide the decision between outpatient and inpatient therapy. Using procalcitonin as a biomarker for severe infection may further assist with risk stratification. Most outpatients with community-acquired pneumonia do not require microbiologic testing of sputum or blood and can be treated empirically with a macrolide, doxycycline, or a respiratory fluoroquinolone. Patients requiring hospitalization should be treated with a fluoroquinolone or a combination of beta-lactam plus macrolide antibiotics. Patients with severe infection requiring admission to the intensive care unit require dual antibiotic therapy including a third-generation cephalosporin plus a macrolide alone or in combination with a fluoroquinolone. Treatment options for patients with risk factors for Pseudomonas species include administration of an antipseudomonal antibiotic and an aminoglycoside, plus azithromycin or a fluoroquinolone. Patients with risk factors for methicillin-resistant Staphylococcus aureus should be given vancomycin or linezolid, or ceftaroline in resistant cases. Administration of corticosteroids within 36 hours of hospital admission for patients with severe community-acquired pneumonia decreases the risk of adult respiratory distress syndrome and length of treatment. The 23-valent pneumococcal polysaccharide and 13-valent pneumococcal conjugate vaccinations are both recommended for adults 65 years and older to decrease the risk of invasive pneumococcal disease, including pneumonia.

Together, influenza and pneumonia are the eighth leading cause of mortality among adults in the United States and result in more than 60,000 deaths annually.14 Community-acquired pneumonia (CAP) disproportionately affects persons who are very young or very old, with an annual incidence of 9.2 to 33 per 1,000 person-years.1,5 Out of an estimated 878,000 adults 45 years and older who were hospitalized with a primary diagnosis of CAP in 2010, 71% were 65 years or older, and 10% to 20% required admission to the intensive care unit (ICU).1,2,6,7 Pneumococcal pneumonia alone was responsible for 866,000 outpatient visits in 2004.8 In the United States, annual health care costs associated with CAP range from $10.6 to $17 billion and are expected to grow as the proportion of older persons increases.1,2,4 Inpatient care accounts for more than 90% of pneumonia-related health expenditure.2,3,5


For patients with severe community-acquired pneumonia, corticosteroids decrease the risk of adult respiratory distress syndrome and modestly reduce intensive care unit and hospital stays, duration of intravenous antibiotic treatment, and time to clinical stability without increasing major adverse events.

Adults 65 years and older should routinely receive the 13-valent pneumococcal conjugate vaccine (PCV13; Prevnar 13) and the 23-valent pneumococcal polysaccharide vaccine (PPSV23; Pneumovax 23), preferably PCV13 first followed by PPSV23 in 12 months.

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Clinical recommendationEvidence ratingReferences

In patients with suspected CAP, chest radiography or lung ultrasonography should be performed to confirm the diagnosis.


6, 13, 17, 18

Testing for specific pathogens should be ordered only when it would alter standard empiric therapy, which is rare in outpatients.


6, 19, 22, 25

Use of procalcitonin testing can assist in the management of CAP and reduce antibiotic exposure without compromising patient safety.



Validated mortality and pneumonia severity assessment tools should be used to determine the appropriate level of care for patients with CAP.


6, 31, 34

Patients with CAP who are admitted to the intensive care unit should be treated with dual antibiotic therapy.


6, 43

For patients with severe CAP, use of corticosteroids within 36 hours improves outcomes.



Influenza vaccination for all patients and pneumococcal vaccination for patients 65 years and older and other high-risk patients are the mainstays of CAP prevention.



CAP = community-acquired pneumonia.

A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, go to


Clinical recommendationEvidence ratingReferences

In patients with suspected CAP, chest radiography or lung ultrasonography should be performed to confirm

The Authors

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ALEXANDER KAYSIN, MD, MPH, is an assistant professor in the Department of Family Medicine at the University of North Carolina at Chapel Hill....

ANTHONY J. VIERA, MD, MPH, is an associate professor in the Department of Family Medicine at the University of North Carolina at Chapel Hill.

Address correspondence to Alexander Kaysin, MD, MPH, University of North Carolina at Chapel Hill, 590 Manning Dr., Chapel Hill, NC 27599 (e-mail: Reprints are not available from the authors.

Author disclosure: No relevant financial affiliations.


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