History and exam

Key diagnostic factors

Symptoms of a lower respiratory tract infection such as cough are frequently seen in people with CAP.[1][64]

  • Cough is one of the most common symptoms present in patients with CAP.[1] Cough is usually productive with mucopurulent sputum.

  • The presence of mucopurulent sputum is associated with bacterial pneumonia.[1] Scant or watery sputum is associated with an atypical pathogen.[1]

  • Older patients may not present with cough and are more likely to have non-specific symptoms (e.g., confusion) and may be afebrile.[1]

Dyspnoea is frequently seen in people with CAP.[1][64] 

  • Dyspnoea is one of the most useful predictive symptoms of CAP in the community (together with fever, tachypnoea, pleuritic chest pain, and new/focalising signs on physical examination of chest) when compared with the gold standard of radiological diagnosis of CAP.[1]

Pleuritic chest pain is frequently reported in people with CAP,[1][64] occuring in 30% of patients.[99]

  • Pleuritic chest pain is one of the most useful predictive symptoms of CAP in the community (together with fever, dyspnoea/tachypnoea, and new/focalising signs on physical examination of chest) when compared with the gold standard of radiological diagnosis of CAP.[1]

Rigors or night sweats are usually present in people with CAP, but are less common in older patients.[1][64] 

Fever is commonly seen in people with CAP, although older people may be afebrile.[1][64]

  • A fever (>38ºC [>100ºF]) is one of the most useful predictive symptoms of CAP in the community (together with dyspnoea/tachypnoea, pleuritic chest pain, and new/focalising signs on physical examination of chest) when compared with the gold standard of radiological diagnosis of CAP.[1]

  • Older people may be afebrile.[1]

New focal chest signs are frequently present on examination in people with CAP.[1][64]

  • You may hear crackles, decreased breath sounds, dullness to percussion, and wheeze.

  • Tachypnoea is one of the most useful predictive symptoms of CAP in the community (together with fever, dyspnoea, pleuritic chest pain, and new/focalising signs on physical examination of chest) when compared with the gold standard of radiological diagnosis of CAP.[1]

Confusion is frequently seen in older people presenting with CAP.[1][64]

  • Older people with CAP often present with non-specific symptoms such as confusion or worsening of underlying diseases, and may be afebrile.[1][64][65]

  • Atypical presentations (without obvious chest signs) of CAP may include confusion, such as in the case of legionella pneumonia, which may present as constitutional upset, diarrhoea, and confusion.[73]

Your history should cover the following risk factors to help assess the likelihood of CAP.[1][64]

(*denotes a strong risk factor for CAP)

  • Age ≥65 years*

    • Incidence of CAP increases significantly with age. Advanced age is associated with a higher mortality from CAP.[10]

  • Residence in a nursing home*

    • Mortality rates due to pneumonia in nursing home residents have been reported to reach 55%.[78][79] 

    • Nursing home residents also have an increased risk of aspiration pneumonia.[80]

  • Contact with children*

    • Regular contact with children is associated with an increased risk of CAP.[50]

  • Respiratory chronic diseases

    • COPD*, asthma, and bronchitis are associated with a 2-fold to 4-fold increased risk of CAP.[6] 

    • COPD is an independent risk factor for mortality in patients with CAP.[39]

  • Other chronic comorbidities

    • Chronic heart disease.[6][39] 

    • Diabetes[6][39] – the risk of severe pneumococcal bacteraemia is higher in people with diabetes.[55]

  • Alcohol use/misuse*

    • People who consume alcohol at all or in higher amounts have an 83% higher risk of CAP compared with people who consume no alcohol or lower amounts (relative risk of 1.83).[44] For every 10-20 g higher alcohol intake per day, there is an 8% increase in the risk of CAP.[44]

  • Smoking*

    • Smoking is an independent risk factor for developing CAP.[81]

    • Passive smoking at home is also a risk factor for CAP in people aged 65 years or older.[43][81]

  • Poor oral hygiene

    • Poor oral hygiene (particularly dental dysaesthesia and wearing dental prosthesis) may contribute to a higher risk of CAP in adults.[82]

  • Proton pump inhibitors

    • Associated with the occurrence of CAP.[47]

  • H2 antagonists

    • Associated with the occurrence of CAP.[49]

  • Prescribed opioids

    • In particular, immunosuppressive opioids are associated with CAP.[60]

Other diagnostic factors

Non-specific symptoms such as myalgia have been reported by people with CAP.[1]

  • Older people with CAP frequently present with non-specific symptoms and worsening of pre-existing conditions.[1]

Non-specific symptoms such as malaise have been reported by people with CAP.[1]

  • Older people with CAP frequently present with non-specific symptoms and worsening of pre-existing conditions.[1]

Non-specific symptoms such as anorexia have been reported by people with CAP.[1]

  • Older people with CAP frequently present with non-specific symptoms and worsening of pre-existing conditions.[1]

Non-specific symptoms such as lethargy have been reported by people with CAP.[1]

  • Older people with CAP frequently present with non-specific symptoms and worsening of pre-existing conditions.[1]

  • Older people frequently present with non-specific symptoms and worsening of pre-existing conditions.[1]

Atypical presentations (without obvious chest signs) of CAP may include sore throat.

  • Mycoplasma pneumonia in young adults may present as sore throat, headache, nausea, abdominal pain, and diarrhoea.[73]

Atypical presentations (without obvious chest signs) of CAP may include headache.

  • Mycoplasma pneumonia in young adults may present as sore throat, headache, nausea, abdominal pain, and diarrhoea.[73]

Atypical presentations (without obvious chest signs) of CAP may include nausea.

  • Mycoplasma pneumonia in young adults may present as sore throat, headache, nausea, abdominal pain, and diarrhoea.[73]

Atypical presentations (without obvious chest signs) of CAP may include abdominal pain.

  • Mycoplasma pneumonia in young adults may present as sore throat, headache, nausea, abdominal pain, and diarrhoea.[73]

Atypical presentations (without obvious chest signs) of CAP may include diarrhoea.

  • Mycoplasma pneumonia in young adults may present as sore throat, headache, nausea, abdominal pain, and diarrhoea.[73]

  • Legionella pneumonia may present as constitutional upset, diarrhoea, and confusion.[73]

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