History and exam

Key diagnostic factors

common

fever

Consider the possibility of pneumonia if a child presents with a fever, particularly if associated with one or more of the following: tachypnea; chest crackles; nasal flaring; chest indrawing; cyanosis; oxygen saturation ≤95% on room air.[9][19]​​

One multicenter study covering 2358 children who had radiographic evidence of pneumonia found that 91% had fever.[4] Fever >99.5°F (>37.5°C) had a likelihood ratio range of 1.7 to 1.8 for predicting radiographically confirmed CAP (sensitivity 80% to 92%, specificity 47% to 54%) in a systematic review of 23 studies involving 13,833 children with suspected pneumonia.[5]

A fever that persists for >7 days raises suspicion for empyema, and a prolonged high fever is also a typical feature of necrotizing pneumonia.​[2][3][9]

cough

Cough is common but not always present, particularly in the early stages of illness.[3] It was present in 95% of children in one multicenter study of 2358 cases of radiographically confirmed CAP.[4]

Production of foul-smelling sputum raises suspicion of necrotizing pneumonia.[3]

hypoxemia

Use pulse oximetry to check for hypoxemia.

Hypoxemia and signs of increased work of breathing were the two symptoms or signs most strongly correlated with radiographic evidence of pneumonia in one systematic review of 23 prospective cohort studies involving a total of 13,833 children with suspected pneumonia.[5]​ Oxygen saturation ≤96% on pulse oximetry was found to have a likelihood ratio of 2.8 (95% CI 2.1 to 3.6), a sensitivity of 64%, and a specificity of 77% for pneumonia. Conversely, oxygen saturation >96% was a strong predictor that the child would not have radiographic evidence of pneumonia (likelihood ratio 0.47, 95% CI 0.32 to 0.67).[5]

Arrange hospital admission for any child or infant with CAP who has sustained peripheral oxygen saturation <90% on room air.[1] This has been shown to be predictive of failure of outpatient oral antibiotic treatment.

tachypnea

A common but nonspecific sign of CAP.[1][9]​​

Respiratory rate (RR) >40 breaths/minute had a likelihood ratio for predicting radiographically confirmed CAP of 1.5 (95% CI 1.3 to 1.7) (sensitivity 79%, specificity 51%) in one systematic review of 23 prospective cohort studies involving a total of 13,833 children with suspected pneumonia.[5]

Be aware, however, that some children with CAP have a normal RR.[9]

A raised RR compared with age-specific norms has been found to correlate well with hypoxemia.[20]​ One study found that in infants <1 year, a RR ≥70 breaths/minute had a sensitivity of 63% and specificity of 89% for hypoxemia.[27]

Arrange hospital admission for any child with tachypnea as indicated by: RR of >60 at age 0-2 months; >50 at age 2-12 months; >40 at age 1-5 years; >20 at age >5 years.[1]

increased work of breathing

Look for: suprasternal, intercostal, or subcostal retractions; nasal flaring; or head bobbing.[1][9][17]

Arrange hospital admission for any child or infant with CAP who has signs of substantially increased work of breathing (e.g., retractions, nasal flaring, use of accessory muscles).[1]

Signs of increased work of breathing and hypoxemia were the two symptoms or signs most strongly correlated with radiographic evidence of pneumonia in one systematic review of 23 prospective cohort studies involving a total of 13,833 children with suspected pneumonia.[5]​ Increased work of breathing was found to have a likelihood ratio of 2.1 (95% CI 1.6 to 2.7) for predicting radiographically confirmed pneumonia.[5]

Grunting is a sign of severe disease and impending respiratory failure.[1]

abnormal auscultatory findings

Signs of CAP on auscultation may include abnormal or decreased breath sounds such as crackles, rales, crepitation, wheeze and rhonchi.[1] One study found that crackles and bronchial breathing had a sensitivity of 75% and specificity of 57% for pneumonia.[27]

Note, however, that a systematic review of 23 studies involving a total of 13,833 children with suspected pneumonia found that no auscultatory finding was significantly associated with a radiographic diagnosis of CAP, perhaps because of the relative subjectivity of auscultatory signs and difficulty interpreting them in children.[5]

Arrange hospital admission for any child with auscultatory findings that suggest complicated CAP.[1][9] An absence of breath sounds, with a dull percussion note, is suggestive of CAP complicated by pleural effusion.[9] Fremitus is increased in uncomplicated CAP (but reduced if pleural effusion has developed).[2]

Early inspiratory crackles
Early inspiratory crackles

Auscultation sounds: Early inspiratory crackles

​

Late inspiratory crackles (rales)
Late inspiratory crackles (rales)

Auscultation sounds: late inspiratory crackles (rales)

​

uncommon

cyanosis

A sign of severe hypoxemia.[1] Arrange hospital admission if present.[1]

apnea

Intermittent apnea may be seen, particularly in infants.[1][9] Arrange hospital admission for any child with this; it is a sign of severe CAP.[1][9]

Other diagnostic factors

common

dyspnea

Present in 70% of children in one multicenter study of 2358 cases with radiographic evidence of pneumonia.[4]

Arrange hospital admission for any child or infant with CAP who has significant dyspnea.[1]

tachycardia

Check the pulse rate for any signs of tachycardia.​[3][9]​ 

Tachycardia is defined according to age-related norms. It is usually considered to be 2 standard deviations above the age-standardized normal heart rate or <10th percentile for age if the child is <1 year old.

wheeze

Only an indicator of possible CAP if accompanied by fever and/or hypoxemia.[1]​ One study of 526 children presenting to the emergency department with wheeze found that only 4.9% of those with wheeze alone had radiographic evidence of pneumonia, compared with 20.6% of those who also had both fever and hypoxemia (oxygen saturation <92%).[23]

Wheeze on its own is a poor indicator of possible CAP and raises suspicion of an alternative diagnosis, such as viral wheeze or an exacerbation of asthma. The presence of wheeze has been found in several studies to be a negative predictor of radiographic CAP.[10][21][22]​​

uncommon

prolonged capillary refill time (CRT)

A CRT >2 seconds is a sign of severe disease.[9]

chest pain

More commonly reported in older children and adolescents.[5]

Pleuritic chest pain raises suspicion of empyema or necrotizing pneumonia.​[3][9]

abdominal pain

Is occasionally the main presenting symptom, especially in children <5 years old.[1]

vomiting

May be present.[9]

Consider hospital admission if the child is vomiting, dehydrated, or unable to take oral medication for any other reason.[1][9]

difficulty feeding

Most often seen in infants.

Consider hospital admission, particularly if there are signs of dehydration.[1][9][17]

agitation or altered mental status

May be an indicator of hypoxemia. Arrange hospital admission if present.[1]

night sweats

Raises suspicion of necrotizing pneumonia, especially if the child appears very unwell and has a high fever, cough, and tachypnea that last for several days.​[2][3]

Risk factors

strong

younger age (<2 years old)

Children younger than 2 years old are more likely to develop CAP and especially complicated CAP (CCAP).[1]​​[2][3]​ Age <5 years is a risk factor for severe CAP.[9]

male sex

Boys have a higher incidence of CAP across all ages.[1]​​[2][3]

prematurity

Prematurity is one of the most important risk factors associated with respiratory diseases. CAP affects preterm infants at a higher rate than infants of more advanced gestational age.[1]​​[2][3]​ Prematurity is also a risk factor for severe disease.[9]

chronic underlying condition

Among the long-term conditions associated with a higher risk of developing CAP, and particularly complicated CAP, are: immunodeficiency; malnutrition; chronic lung disease; congenital heart disease; neurodisability; cerebral palsy; cystic fibrosis; and a history of severe and/or complicated and/or recurrent pneumonia.[1]​​[2][3]

history of severe and/or complicated and/or recurrent pneumonia

A history of recurrent pneumonia or of severe or complicated pneumonia increases the risk of progressing to severe or complicated CAP.[3]

inhaled foreign body

An undiagnosed and retained inhaled foreign body may result in CAP or complicated CAP (e.g., atelectasis, bronchiectasis, lung abscess).[2]

indoor air pollution

Indoor air pollution caused by cooking and heating with biomass fuels, such as wood or dung, increases the risk of CAP.[1]​​[2][3]

overcrowded housing

Data suggest that household crowding puts young children at increased risk of acute lower respiratory infection because it increases the rate of cross-infection among the family. Pathogen agents are easily and rapidly transmitted in crowded and ill-ventilated rooms where people are talking, sneezing, or coughing, thanks to air droplets and aerosols.[1]​​[2][3]

parental smoking

Children exposed to passive smoking have an increased likelihood of emergency unit visit and hospital admission for respiratory illness; however, these data are not specific for CAP.[1]​​[2][3]

anatomic lesion such as vascular ring or sling

A vascular ring or sling (a type of congenital aortic arch anomaly) can result in compression of the trachea and predispose a child to recurrent lower respiratory tract infections.[13][14]

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