Community-acquired pneumonia in children: Outpatient treatment

Author:

William J Barson, MD

Section Editors:

Morven S Edwards, MD

George B Mallory, MD

Deputy Editor:

Mary M Torchia, MD

Contributor Disclosures

All topics are updated as new evidence becomes available and ourpeer review processis complete.

Literature review current through:Nov 2016.|This topic last updated:Jan 13, 2016.

INTRODUCTION—Community-acquired pneumonia (CAP) is defined as an acute infection of the pulmonary parenchyma in a patient who has acquired the infection in the community, as distinguished from hospital-acquired (nosocomial) pneumonia. CAP is a common and potentially serious illness with considerable morbidity.

The Pediatric Infectious DiseasesSociety/InfectiousDiseases Society of America and the British Thoracic Society have developed clinical practice guidelines for the evaluation and treatment of CAP in children [1,2].

The outpatient treatment of CAP in infants and children will be reviewed here. Neonatal pneumonia and inpatient treatment of pneumonia are discussed separately, as are the epidemiology, etiology, clinical features, and diagnosis. (See"Neonatal pneumonia"and"Pneumonia in children: Inpatient treatment"and"Pneumonia in children: Epidemiology, pathogenesis, and etiology"and"Community-acquired pneumonia in children: Clinical features and diagnosis".)

INDICATIONS FOR HOSPITALIZATION—The decision to hospitalize a child with CAP is individualized based upon age, underlying medical problems, and clinical factors including severity of illness (table 1) [1-3]. Hospitalization generally is warranted for infants younger than three to six months of age, unless a viral etiology orChlamydia trachomatisis suspected and they are normoxemic and relatively asymptomatic. Hospitalization is also warranted for a child of any age whose family cannot provide appropriate care and assure compliance with the therapeutic regimen. Additional indications for hospitalization include [1,2]:

●Hypoxemia (oxygen saturation <90 percent in room air at sea level)

●Dehydration, or inability to maintain hydration orally; inability to feed in an infant

●Moderate to severe respiratory distress: Respiratory rate >70 breaths per minute for infants <12 months of age and >50 breaths per minute for older children; retractions; nasal flaring; difficulty breathing; apnea; grunting

●Toxic appearance (more common in bacterial pneumonia and may suggest a more severe course) [4]

●Underlying conditions that may predispose to a more serious course of pneumonia (eg, cardiopulmonary disease, genetic syndromes, neurocognitive disorders), may be worsened by pneumonia, even viral pneumonia (eg, metabolic disorder) or may adversely affect response to treatment (eg, immunocompromised host)

●Complications (eg,effusion/empyema)(see"Epidemiology; clinical presentation; and evaluation of parapneumonic effusion and empyema in children"and"Management and prognosis of parapneumonic effusion and empyema in children")

●Suspicion or confirmation that CAP is due to a pathogen with increased virulence, such asStaphylococcus aureusor group A streptococcus

●Failure of outpatient therapy (worsening or no response in 48 to 72 hours) (see'Treatment failure'below)

EMPIRIC THERAPY

Overview—Children with CAP who are treated in the outpatient setting typically are treated empirically; tests to identify a microbiologic etiology are not recommended for most children who are well enough to be treated in the outpatient setting [1,2]. Decisions regarding empiric therapy are complicated by the substantial overlap in the clinical presentation of bacterial and nonbacterial pneumonias [2,5,6]. Treatment decisions are usually based upon algorithms that include patient age, epidemiologic and clinical information, and diagnostic laboratory and imaging studies (if such studies were obtained) (table 2andtable 3) [4]. Consultation with a specialist in infectious disease may be helpful in children with medication allergies or comorbid conditions. (See"Community-acquired pneumonia in children: Clinical features and diagnosis"and"Pneumonia in children: Epidemiology, pathogenesis, and etiology", section on 'Etiologic agents'.)

There are few randomized controlled trials to guide the choice of empiric antibiotics in children with CAP. Factors that must be considered include the spectrum of likely pathogens, antimicrobial susceptibility, simplicity, tolerability, palatability, safety, and cost [7]. The recommendations of most guidelines are based upon observations regarding the susceptibility of the most likely pathogen or pathogens, rather than on evidence of the superiority of one antibiotic over another [1,2]. The clinical response to the most commonly used antimicrobials appears to be similar, regardless of etiology [8-10]. The response within the first 48 to 72 hours of empiric therapy (or lack of therapy if a viral etiology is most likely) helps to determine whether additional evaluation or changes in therapy are necessary. (See'Monitoring response'below.)

Children <5 years

Neonates—The treatment of neonatal pneumonia is discussed separately. (See"Neonatal pneumonia".)

One to six months—Infants younger than three to six months of age with suspected bacterial CAP or who are hypoxemic (oxygen saturation <90 percent in room air at sea level) should be admitted to the hospital for empiric therapy. (See"Pneumonia in children: Inpatient treatment", section on 'Empiric therapy'.)

In afebrile infants one to four months of age with CAP, the most likely bacterial pathogen isC. trachomatis(ie, "afebrile pneumonia of infancy") [4,11]. Infants who are thought to have afebrile pneumonia of infancy can be treated in the outpatient setting if they are not hypoxemic and remain afebrile [4]. (See"Chlamydia trachomatis infections in the newborn", section on 'Treatment'.)

Bordetella pertussisis a less common, but more severe, cause of pneumonia in young infants; fever may or may not be present. LikeC. trachomatis,B. pertussisis susceptible to the macrolides [4]. However, young infants who are thought to haveB. pertussis-associated pneumonia should be admitted to the hospital because they are at risk for complications (eg, hypoxia, apnea, pulmonary hypertension, etc). (See"Pertussis infection in infants and children: Clinical features and diagnosis", section on 'Infants'and"Pertussis infection in infants and children: Treatment and prevention", section on 'Hospitalization'.)

Six months to five years

Suspected viral etiology—Viral etiologies predominate during early childhood. Viral pneumonia (suggested by gradual onset, preceding upper respiratory tract symptoms, diffuse findings on auscultation, lack of toxic appearance (table 3)) shouldnotbe treated with antibiotics. Antiviral agents generally are not used for viral pneumonia in the outpatient setting, with the exception of neuraminidase inhibitors for influenza pneumonia. (See"Community-acquired pneumonia in children: Clinical features and diagnosis", section on 'Clues to etiology'and"Pneumonia in children: Epidemiology, pathogenesis, and etiology", section on 'Etiologic agents'and"Seasonal influenza in children: Prevention and treatment with antiviral drugs", section on 'Antiviral therapy'.)

Infants and young children with known or suspected chronic disease (eg, cardiopulmonary disease, neuromuscular disease, etc) are at increased risk for severe or complicated viral lower respiratory tract infection (LRTI). If such children are not admitted to the hospital, they merit close monitoring in the outpatient setting.

Suspected influenza– In children with suspected influenza who are at increased risk of complications (table 4), initiation of antiviral treatment is recommended as soon as possible; laboratory confirmation should not delay initiation of antiviral therapy. The diagnosis and treatment of influenza in children are discussed separately. (See"Seasonal influenza in children: Prevention and treatment with antiviral drugs", section on 'Antiviral therapy'and"Seasonal influenza in children: Clinical features and diagnosis", section on 'Clinical features'.)

Suspected bacterial etiology—Streptococcus pneumoniaeis the most frequent cause of "typical" bacterial pneumonia in children of all ages [1,2]. Bacterial pneumonia in preschool children usually causes more severe infection, with abrupt onset and moderate to severe respiratory distress, which may require inpatient therapy. (See'Indications for hospitalization'above and"Pneumonia in children: Inpatient treatment", section on 'Empiric therapy'.)

For children younger than five years who are thought to have bacterial CAP based upon clinical presentation, examination findings, and supportive radiographic or laboratory data if obtained (eg, lobar consolidation on radiograph, white blood cell count [WBC]>15,000/microL,C-reactive protein >35 to 60mg/L[3.5 to 6mg/dL](table 3)), but do not require inpatient therapy,amoxicillinis usually considered the drug of choice [1,2,12]. We suggest high dose amoxicillin (90 to 100mg/kgper day divided into two or three doses; maximum dose 4g/day)(table 2).

Amoxicillinis preferred because it is effective against the majority of bacterial pathogens for CAP in this age group, is well tolerated, and is inexpensive [1,2]. The higher dose of amoxicillin is suggested because of the concern for antibiotic-resistantS. pneumoniaeisolated from patients with community-acquired respiratory tract infections [13,14]. Amoxicillin is more active in vitro than any of the oral cephalosporins against these isolates. Universal infant immunization with the 7-valent pneumococcal conjugate vaccine (PCV7) resulted in a decreased prevalence of penicillin resistant pneumococci. However, it was associated with the emergence of antibiotic-resistant invasive serotypes, some of which are included in the13-valent pneumococcal conjugate vaccine(PCV13) (eg, serotype 19A) [1]. The effects of PCV13 on antibiotic resistance are preliminary and suggest an increasing susceptibility to penicillin andceftriaxone. The proportion of total isolates with penicillin MICs >2mcg/mLreported by the Pediatric Multicenter Pneumococcal Surveillance Group decreased from 21.2 to 8.2 percent between 2008-2009 and 2011 [15]. A similar decrease was seen in isolates with a ceftriaxone MIC >1mcg/mL. Pending additional data confirming this trend, we continue to suggest high-dose rather than standard dose amoxicillin (ie, 40 to 45mg/kgper day) when amoxicillin is used to treat CAP in children. (See"Resistance of Streptococcus pneumoniae to beta-lactam antibiotics"and"Resistance of Streptococcus pneumoniae to the macrolides, azalides, lincosamides, and ketolides".)

Although there are prospective, comparative data supporting the efficacy of twice daily dosing ofamoxicillinfor the treatment of acute otitis media [16-18], similar data are not available for documented pneumococcal pneumonia in children. Unless the etiologic agent is identified as aS. pneumoniaeisolate with a minimum inhibitory concentration (MIC) of <2mcg/mL,dividing the total daily 90 to 100mg/kgdose of amoxicillin into three doses may be warranted. Twice daily dosing for pneumonia due to aS. pneumoniaeisolate with an MIC of 2mcg/mLis predicted to achieve a clinical and microbiologic cure in only 65 percent of children, whereas the same total daily dose divided in three equal portions is predicted to achieve a cure in 90 percent [19].

For children with non-type 1 hypersensitivity reactions to penicillin (table 5), a second- or third-generation cephalosporin (eg,cefdinir) is an acceptable alternative toamoxicillin[1]. For children with type 1 hypersensitivity reactions (table 5) to penicillin,clindamycinor a macrolide may be used [1,2]. However, if local resistance rates are high for clindamycin and macrolides,levofloxacinorlinezolidmay be preferable. Doses are provided in the table (table 2).

For the infant or child who is suspected to have bacterial CAP and is unable to tolerate liquids at the time of presentation, asingleinitial dose ofceftriaxone(50 to 75mg/kg)may be administered intramuscularly or intravenously before starting oral antibiotics [20,21]. Administration of intramuscular ceftriaxone to children with uncomplicated CAP who are able to tolerate liquids is expensive and provides no benefit over oral antibiotics.

Suspected atypical pneumoniaMycoplasma pneumoniaeandChlamydophilapneumoniaeare less common thanS. pneumoniaein children younger than five years with CAP [5]. However, they can occur in this age group and should be considered in children without a pneumonia-associated complication who fail to improve after 48 to 72 hours of empiric therapy forS. pneumoniae(eg,amoxicillin), at which time a macrolide could be added or substituted (table 2). (See'Treatment failure'below.)

Children ≥5 years

Suspected typical or atypical bacterial etiology—S. pneumoniaeis the most frequent cause of "typical" bacterial pneumonia in children of all ages [1,2]. However, in otherwise healthy children five years and older with CAP who are not ill enough to require hospitalization,M. pneumoniaeandC. pneumoniaeare the most likely pathogens [4,11,22].

We suggest macrolide antibiotics for initial empiric therapy for CAP in children older than five years who are treated as outpatients [1,4]. However, the prevalence of macrolide-resistantM. pneumoniaeis increasing in some geographic regions, including Asia, Europe, Israel, and the United States [23-31]. The reported prevalence of resistance amongM. pneumoniaeisolates ranges from approximately 10 percent in the United States to 90 percent in China and some parts of Japan [25,28,32,33]. Alternative agents includelevofloxacinanddoxycycline[1]. The long-held concern for enamel staining associated with doxycycline in children younger than eight years use is unfounded [34]. The British Thoracic Society clinical practice guideline suggestsamoxicillinas the first-line therapy for children of all ages [2]. Doses are provided in the table (table 2).

Among the macrolide antibiotics,clarithromycinandazithromycinhave a more convenient dosing schedule and fewer side effects thanerythromycin, but erythromycin is less expensive [8,35,36]. Macrolide antibiotics may provide coverage forS. pneumoniae, which is the most frequent typical bacterial pathogen for all age groups [37-39]. However, approximately 40 to 50 percent ofS. pneumoniaeisolates are resistant to macrolides. Failure to respond to macrolide therapy may indicate the development of a complication, a macrolide-resistant pathogen,and/orthe need to alter therapy to provide better pneumococcal coverage. (See'Treatment failure'below.)

Given the significant resistance ofS. pneumoniaeto macrolides, fluoroquinolones (eg,levofloxacin,moxifloxacin) are another reasonable alternative for the outpatient treatment of CAP. In addition to their excellent gram-negative spectrum, the fluoroquinolones are active against a number of the pathogens responsible for CAP, including beta-lactam-susceptible and non-susceptibleS. pneumoniae,M. pneumoniae, andC. pneumoniae[40]. However,S. pneumoniaeresistant to levofloxacin has been identified [41].

Suspected influenza—Initiation of antiviral treatment for influenza (eg,oseltamivir) as soon as possible is recommended for children with suspected influenza who are at high risk for complications of influenza pneumonia (table 4); laboratory confirmation should not delay initiation of antiviral therapy. The diagnosis and treatment of influenza in children are discussed separately. (See"Seasonal influenza in children: Prevention and treatment with antiviral drugs", section on 'Antiviral therapy'.)

Suspected aspiration pneumonia—Community-acquired aspiration pneumonia is usually treated withamoxicillin-clavulanate.Clindamycinis an alternative for patients allergic to penicillin. Doses are provided in the table (table 2). In neurologically compromised adolescents who may be prone to aspiration events, empiric treatment withmoxifloxacin(400 mg once per day) is an alternative. Moxifloxacin is active against anaerobic bacteria, as well as the usual treatable causes of CAP:S. pneumoniae,M. pneumoniae, andC. pneumoniae. Fluoroquinolone antibiotics generally are not recommended for children younger than 18 years of age when there is a safe and effective alternative. (See"Fluoroquinolones", section on 'Use in children'.)

Duration—Few randomized controlled trials have been performed to determine the appropriate duration of antimicrobial therapy in radiographically confirmed childhood pneumonia [2]. Current practice in the developed world determines the duration of therapy based upon the age of the host, likely causative agent, and severity of disease:

●We suggest that infants ≥4 months and children with uncomplicated pneumonia suspected or confirmed to be caused by routine pathogens (ie,S. pneumoniae,M. pneumoniae,C. pneumoniae) be treated for 7 to 10 days; the course ofazithromycinis five days [1,8]

●The duration of treatment forC. trachomatispneumonia in young infants is discussed separately (see"Chlamydia trachomatis infections in the newborn", section on 'Treatment')

A meta-analysis found three days of oral antimicrobial therapy to be as effective as five days for nonsevere CAP in children aged 2 to 59 months [42]. However, the studies included in the meta-analysis were performed in developing countries, where it is not feasible to perform radiographs or evaluation for a microbiologic etiology; pneumonia was diagnosed by the World Health Organization (WHO) criteria, which are based on clinical findings and respiratory rate thresholds. In another study, only 14 percent of children diagnosed with nonsevere pneumonia by the WHO criteria had radiographic evidence of pneumonia [43]. Many of the children in the meta-analysis probably had viral pneumonia, for which antibiotic therapy is not warranted. This is supported by a subsequent randomized trial in which the clinical outcomes did not differ for children aged 2 to 59 months who were diagnosed with nonsevere pneumonia by the WHO criteria and treated for three days withamoxicillinversus placebo [44].

In a subsequent randomized trial in a developed country, 4 of 10 children who received three days of outpatient treatment (amoxicillin80mg/kgper day divided in three doses) for radiologically confirmed CAP required rescue therapy or hospitalization versus none of 12 children treated for 10 days [45]. In the second stage of the trial, five days of treatment (amoxicillin 80mg/kgper day divided in three doses) was as effective as 10 days in preventing the need for rescue therapy or hospitalization, but with fewer than 60 patients in each arm, the study may have been underpowered to detect a difference. Additional, larger studies are necessary to confirm these results before we suggest five days of therapy for uncomplicated CAP.

Monitoring response—Children with CAP who are treated as outpatients (including those who were not initially treated with antibiotics) should have follow-up within 24 to 48 hours [1,2]. Follow-up may be performed by phone. Children with CAP who are appropriately treated generally show signs of improvement within 48 to 72 hours.

Treatment failure—Among patients who do not improve as anticipated, the following possibilities must be considered [1,2,14,46]:

●Alternative or coincident diagnoses (eg, foreign body aspiration) (see"Community-acquired pneumonia in children: Clinical features and diagnosis", section on 'Differential diagnosis')

●Development of complications (see"Community-acquired pneumonia in children: Clinical features and diagnosis", section on 'Complications')

●Ineffective antibiotic coverage (lack of coverage for the actual etiology or resistant organism)

Worsened condition—Patients whose condition has worsened require additional evaluation and hospitalization. They also should undergo radiologic evaluation to look for the development of complications. Laboratory tests should be performed to try to establish a microbiologic diagnosis. (See"Community-acquired pneumonia in children: Clinical features and diagnosis", section on 'Laboratory evaluation'and"Pneumonia in children: Inpatient treatment", section on 'Hospitalization'.)