Acute bacterial rhinosinusitis in children: Microbiology and management

INTRODUCTION — Acute rhinosinusitis is a disease that results from infection of one or more of the paranasal sinuses. A viral infection associated with the common cold is the most frequent etiology of acute rhinosinusitis, more properly called viral rhinosinusitis. Acute bacterial rhinosinusitis (ABRS) occurs when there is secondary bacterial infection of the sinuses. The clinical course (ie, duration, severity, and improvement or worsening of symptoms (table 1)) distinguishes uncomplicated viral rhinosinusitis from ABRS (table 2), a distinction that is necessary to prevent unnecessary use of antibiotics. (See "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Acute bacterial rhinosinusitis'.)

The microbiology and treatment of ABRS in children will be discussed here. The clinical features and diagnosis of ABRS in children and acute sinusitis and rhinosinusitis in adults are discussed separately. (See "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis" and "Acute sinusitis and rhinosinusitis in adults: Clinical manifestations and diagnosis" and "Uncomplicated acute sinusitis and rhinosinusitis in adults: Treatment".)

Our approach to the management of ABRS in children is generally consistent with recommendations of the American Academy of Pediatrics and the Infectious Diseases Society of America. (See 'Society guideline links' below.)

MICROBIOLOGY

Common pathogens

●Uncomplicated ABRS – Haemophilus influenzae (nontypeable), Streptococcus pneumoniae, and Moraxella catarrhalis are the predominant causes of uncomplicated ABRS [1,2].

Cultures of middle ear fluid obtained by tympanocentesis from children with acute otitis media (AOM) are used as a surrogate for cultures of the paranasal sinuses because AOM and ABRS have similar pathogenesis and microbiology [3,4]. Although culture of material aspirated from the sinus yielding ≥10⁴ colony-forming units/mL of bacteria is the standard for determining the etiology of ABRS [5], sinus aspiration is an invasive procedure that is not routinely performed in children with uncomplicated ABRS. The use of middle ear cultures as a surrogate for cultures of the paranasal sinuses has been validated by studies of sinus aspirates obtained from children with uncomplicated ABRS that were performed before and after the widespread development of antibiotic-resistant S. pneumoniae and the routine use of vaccines against S. pneumoniae [6,7].

Limited data detailing the microbiology of AOM in the post-13-valent pneumococcal conjugate vaccine (PCV13) era highlight the prominence of nontypeable H. influenzae, including beta-lactamase positive isolates [8-12]. In 2017, it was estimated that H. influenzae accounted for approximately 50 to 60 percent of middle ear isolates in AOM, S. pneumoniae for 15 to 25 percent, and M. catarrhalis for 12 to 15 percent [11,13-16]. The presumption that isolates recovered from children with uncomplicated ABRS would be similar was confirmed in a study of 31 children with severe symptoms of acute maxillary sinusitis who underwent sinus aspiration [7]. The most common bacteria recovered were H. influenzae (45 percent), S. pneumoniae (32 percent), and M. catarrhalis (16 percent). (See "Acute otitis media in children: Epidemiology, microbiology, and complications", section on 'Microbiology'.)

Several studies have reported isolation of Staphylococcus aureus from sinus aspirates (obtained endoscopically) or from cultures of the middle meatus in children (most of whom had chronic sinusitis) [17-19]. However, these studies must be interpreted with caution because of methodologic limitations (eg, unknown indication for obtaining culture, lack of quantification, possibility of contamination from the nasal cavity) and because cultures of the middle meatus have not been established as a reliable surrogate for maxillary sinus aspirates in children [20]. Nonetheless, S. aureus, including methicillin-resistant S. aureus, has been recovered from cultures in patients with orbital cellulitis and epidural abscess, presumably complications of ABRS [21-23].

●Complications of ABRS – The microbiology of the complications of ABRS differs from that of uncomplicated ABRS. In retrospective studies of the microbiology of complicated ABRS in children, polymicrobial infections were common and Streptococcus species (eg, Streptococcus anginosus group), other anaerobes, and Staphylococcus species were more frequently isolated than H. influenzae, S. pneumoniae, and M. catarrhalis [24-30].

Antimicrobial susceptibility

●S. pneumoniae – The proportion of isolates of S. pneumoniae that are nonsusceptible to penicillin varies from community to community. Although the incidence of AOM caused by penicillin-resistant S. pneumoniae decreased for several years after PCV13 replaced the 7-valent pneumococcal conjugate vaccine in 2010 [13], cultures from tympanocenteses performed during 2015 to 2019 show an increase in serotypes not included in PCV13 (eg, 35B, 15B/C, and 23B) [12]. Children unimmunized or underimmunized with PCV are more likely to have resistant strains [31].

●H. influenzae – Between 30 to 50 percent of H. influenzae [13] are likely to be beta-lactamase positive and nonsusceptible to amoxicillin. In a single center longitudinal study of AOM pathogens between 2015 and 2019, nearly 49 percent of the H. influenzae isolates were beta-lactamase producing [12].

●M. catarrhalis – Close to 100 percent of M. catarrhalis are likely to be beta-lactamase positive and nonsusceptible to amoxicillin.

Risk factors for antimicrobial resistance — Risks factors for resistant S. pneumoniae and H. influenzae include [31-37]:

●Living in an area with high endemic rates (ie, ≥10 percent) of invasive penicillin-nonsusceptible S. pneumoniae

●Age <2 years

●Daycare attendance

●Antibiotic therapy within the month before presentation

●Hospitalization within the past five days

●Unimmunized or underimmunized with PCV (see "Pneumococcal vaccination in children", section on 'Routine immunization for children <5 years')

WHEN TO INITIATE ANTIBIOTICS — Prompt initiation of antibiotics is necessary for children with ABRS and complications or suspected complications (table 3). (See "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Complications' and 'Complicated ABRS' below.)

There are three clinical presentations of acute bacterial sinusitis (table 1). For children with ABRS and 10 days of symptoms that are neither severe nor worsening, and none of the indications for immediate antimicrobial therapy listed below, we either provide immediate antimicrobial therapy or a three-day period of observation, depending upon patient and caregiver preference. Additional factors that are considered in this decision include severity of symptoms, quality of life, past history of ABRS, cost and ease of administration of antibiotics, and concerns about adverse effects of antibiotics or development of complications. Immediate treatment with antibiotics is preferred to observation because although ABRS may resolve without antibiotics, resolution of symptoms usually occurs earlier and is more likely with than without antibiotics.

We initiate antimicrobial therapy at the time of presentation to medical attention for children with ABRS and one or more of the following [38]:

●A clinical presentation of severe symptoms or worsening symptoms (table 1)

●Receipt of antibiotic therapy in the previous four weeks

●Concurrent bacterial infection (eg, pneumonia, suppurative cervical adenitis, group A streptococcal pharyngitis, acute otitis media)

●Certain underlying conditions, including asthma, cystic fibrosis, immunodeficiency, previous sinus surgery, or anatomic abnormalities of the upper respiratory tract

Randomized trials evaluating antibiotics versus placebo for the treatment of ABRS in children have conflicting results [39-42]. In a meta-analysis of four trials including a total of 382 children [43], the rate of improvement or clinical cure was greater among children treated with antibiotics than with placebo (odds ratio [OR] 2.0, 95% CI 1.2-3.5). However, various limitations of these trials diminish confidence in the conclusions. In a subsequent blinded trial that included nasopharyngeal (NP) swab culture, 510 children ages 2 to 12 years were randomly assigned to receive 10 days of amoxicillin-clavulanate or 10 days of placebo [44]. The reduction in symptom burden score was greater in the amoxicillin-clavulanate group than in the placebo group, and the failure rate (based on an increase in symptoms or inadequate resolution of symptoms) was lower in the amoxicillin-clavulanate group compared with placebo (30 percent versus 43 percent, OR 0.69, 95% CI 0.54-0.88). However, there was no difference in symptom burden score reduction among the subset whose baseline cultures did not detect a pathogen. Until rapid testing for NP pathogens is available, shared decision-making with the family about antibiotic treatment is appropriate. The options include:

●Empiric treatment without testing

●Empiric treatment after testing with plan to discontinue if negative

●Testing with treatment only if test is positive

●Watchful waiting with treatment if symptoms persist beyond three days

There have been no randomized, placebo-controlled trials of antibiotic treatment for ABRS that have used pre- and posttreatment quantitative sinus aspirate culture as the standard for diagnosis and cure. Studies that use clinical and/or radiologic criteria for diagnosis and outcome may underestimate the benefit of antibiotic therapy because they are likely to include at least some patients with self-limited uncomplicated viral upper respiratory tract infection.

OUTPATIENT MANAGEMENT — We generally treat children with ABRS who are well-appearing and without complications or suspected complications (table 3) as outpatients (algorithm 1A-B). Patients older than one year with mild preseptal cellulitis (characterized by slight swelling about the eye such that the eye is open more than 50 percent) and no signs of toxicity may be treated as outpatients provided that follow-up the next day is ensured. (See 'Indications for hospitalization' below and "Preseptal cellulitis", section on 'Treatment'.)

Indications for referral — Children with uncomplicated ABRS can usually be managed by their primary care provider. Indications for consultation with a specialist (eg, infectious disease, otolaryngology, immunology) include [32,45,46]:

●Need for sinus aspiration (see "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Microbiologic evaluation')

●Isolation of resistant or rare pathogens from sinus aspirate (if performed)

●Diagnosed or suspected immunodeficiency

●Recurrent ABRS, particularly if it exacerbates underlying pulmonary conditions (eg, asthma)

Empiric antibiotics — Antibiotics that are used to treat ABRS must provide antibacterial activity against S. pneumoniae, H. influenzae, and M. catarrhalis. (See 'Microbiology' above.)

Additional factors in the choice of therapy include the severity of illness, risk of complications, likelihood of infection with a resistant organism, adverse drug reactions, acceptability, dosing convenience, and adverse effects (algorithm 1A-B) [32].

Mild/moderate ABRS — Mild/moderate ABRS is characterized by a clinical severity score <8 (table 4).

●No risk factors for antibiotic resistance – For children with uncomplicated mild/moderate ABRS who have no risks for antibiotic resistance (table 5), we suggest empiric antimicrobial therapy with standard dose amoxicillin-clavulanate rather than high-dose amoxicillin-clavulanate or other oral antibiotics (eg, amoxicillin, fluoroquinolones, macrolides, or second- or third-generation cephalosporins) (algorithm 1A and table 6) (see 'Risk factors for antimicrobial resistance' above) [32]:

•Amoxicillin-clavulanate 45 mg/kg per day of the amoxicillin component orally in two divided doses (maximum daily dose 1.75 g) for 10 days; in the United States, the 200 or 400 mg amoxicillin/5 mL suspension or the 200 or 400 mg chewable tablet can be used for the appropriate clavulanate ratio.

●Risk factors for antibiotic resistance – For children with uncomplicated mild/moderate ABRS who have one or more risks for antibiotic resistance or whose risk factors for antibiotic resistance are unknown (table 5), we suggest treatment with high-dose rather than standard-dose amoxicillin-clavulanate (algorithm 1A and table 6) (see 'Risk factors for antimicrobial resistance' above):

•Amoxicillin-clavulanate 90 mg/kg per day of the amoxicillin component orally in two divided doses (maximum daily dose 4 g) for 10 days; in the United States, the 600 mg amoxicillin/5 mL suspension or the 1000 mg extended-release tablet can be used for the appropriate clavulanate ratio.

We prefer amoxicillin-clavulanate for the treatment of ABRS in children because of its spectrum of activity, effectiveness, and safety [13,32,40,47]. The clavulanate component provides better activity than amoxicillin against ampicillin-resistant H. influenzae and M. catarrhalis. Beta-lactamase producing nontypeable H. influenzae is an increasingly important cause of respiratory tract infection in the post-13-valent pneumococcal conjugate vaccine (PCV13) era [13,32,48-52].

Other experts suggest amoxicillin for initial therapy of mild/moderate disease [38]. They recommend amoxicillin 45 mg/kg per day orally divided in two doses for children without risk factors for antimicrobial resistance and amoxicillin 90 mg/kg per day orally divided in two doses for children with risk factors for antimicrobial resistance. (See 'Risk factors for antimicrobial resistance' above.)

In a retrospective cohort study of almost 200,000 children and adolescents aged ≤17 years with sinusitis, there was no association between the addition of clavulanate to amoxicillin and treatment failure rate (1.7 percent with clavulanate versus 1.8 percent without [difference -0.03 percent, 95% CI -0.15 to 0.08]) [53]. However, multiple limitations of the study diminish the conclusions that can be drawn.

High-dose amoxicillin-clavulanate provides better activity against penicillin-nonsusceptible S. pneumoniae and ampicillin-resistant nonbeta-lactamase producing H. influenzae than standard-dose amoxicillin-clavulanate [32,49]. However, because of the slight increase in cost and side effects and the stable proportion of penicillin-resistant S. pneumoniae in the post-pneumococcal conjugate vaccine era, we suggest that high-dose amoxicillin-clavulanate be reserved for children with severe disease or increased or unknown risk of antibiotic resistance (either penicillin-nonsusceptible S. pneumoniae or beta-lactamase producing ampicillin-resistant H. influenzae) [32]. (See 'Risk factors for antimicrobial resistance' above.)

In a meta-analysis of randomized trials, fluoroquinolones provided no advantage over beta-lactam antibiotics in the treatment of ABRS in adults [54].

Severe ABRS or risk for severe ABRS — Severe disease is characterized by a clinical severity score ≥8 (table 4). Children with immune-compromising conditions (eg, human immunodeficiency virus [HIV]) are at increased risk for severe disease [32].

For children with severe ABRS or risk for severe ABRS who are treated as outpatients, we suggest treatment with high-dose amoxicillin-clavulanate rather than standard-dose amoxicillin-clavulanate or other oral antibiotics (algorithm 1A and table 6) [32].

●Amoxicillin-clavulanate 90 mg/kg per day of the amoxicillin component orally in two divided doses (maximum daily dose 4 g) for 10 days; in the United States, use the 600 mg amoxicillin/5 mL suspension or the 1000 mg extended-release tablet for the appropriate clavulanate ratio.

We suggest high-dose rather than standard-dose amoxicillin-clavulanate for children with severe ABRS or risk of severe ABRS to provide better activity against penicillin-nonsusceptible S. pneumoniae and ampicillin-resistant nonbeta-lactamase producing H. influenzae [32,49]. (See 'Microbiology' above.)

Alternative single-agent regimens, which have a slightly narrower spectrum of activity than amoxicillin-clavulanate, include a third generation cephalosporin (eg, cefpodoxime, cefdinir) or levofloxacin (algorithm 1B) [55]. Suggested doses are as follows:

●Cefpodoxime 10 mg/kg per day orally divided every 12 hours (maximum daily dose 400 mg) for 10 days

●Cefdinir 14 mg/kg per day orally divided every 12 or 24 hours (maximum daily dose 600 mg) for 10 days

●Levofloxacin 10 to 20 mg/kg per day orally divided every 12 to 24 hours (maximum daily dose 500 mg) for 10 days

Cefpodoxime has greater activity than cefdinir against H. influenzae and is preferred, especially if the patient can take a tablet [56,57]. For the liquid formulation, some clinicians prefer cefdinir because it has a better taste. Although third-generation cephalosporins have been considered inferior to high-dose amoxicillin-clavulanate for penicillin-resistant S. pneumoniae, this may be less of an issue if penicillin-resistant S. pneumoniae remain less common as a cause of acute otitis media and ABRS following the introduction of PCV13. (See 'Microbiology' above.)

Levofloxacin should be reserved for cases in which there is no other safe and effective alternative (eg, in patients who have anaphylaxis with or are intolerant of beta-lactams) [58-60]. In a meta-analysis of randomized trials, fluoroquinolones provided no advantage over beta-lactam antibiotics in the treatment of ABRS in adults [54]. In addition, fluoroquinolones are associated with more severe side effects than amoxicillin-clavulanate [59]. (See "Fluoroquinolones", section on 'Children'.)

Levofloxacin typically remains active against multidrug-resistant pneumococci with high-level resistance to penicillin or third-generation cephalosporins and is an option for treatment when patients have failed initial therapy. (See 'Treatment failure in outpatients' below.)

Children with penicillin contraindications — Alternatives to amoxicillin-clavulanate for children with contraindications to penicillin depend upon the type of adverse reaction (table 6). (See "Penicillin allergy: Immediate reactions" and "Allergy evaluation for immediate penicillin allergy: Skin test-based diagnostic strategies and cross-reactivity with other beta-lactam antibiotics".)

●For children with uncomplicated ABRS who have an immediate reaction (eg, anaphylaxis, bronchospasm) or serious delayed reaction (eg, Stevens-Johnson syndrome, toxic epidermal necrolysis) to penicillin, or a contraindication to cephalosporins, we suggest levofloxacin 10 to 20 mg/kg per day orally divided every 12 or 24 hours [32,60]. (See "Fluoroquinolones", section on 'Children'.)

●For children with uncomplicated ABRS who have a mild delayed hypersensitivity reaction to penicillin antibiotics, we suggest therapy with a third-generation cephalosporin (eg, cefpodoxime or cefdinir):

•Cefpodoxime 10 mg/kg per day orally divided every 12 hours (maximum daily dose 400 mg), or

•Cefdinir 14 mg/kg per day orally divided every 12 or 24 hours (maximum daily dose 600 mg)

Cefpodoxime has greater activity than cefdinir against H. influenzae and is preferred, especially if the patient can take a tablet [56,57]. For the liquid formulation, some clinicians prefer cefdinir because it has a better taste.

Children with vomiting — A single dose of ceftriaxone 50 mg/kg per day (maximum dose 1 g/day) intravenously (IV) or intramuscularly (IM) can be used in children with uncomplicated ABRS and vomiting that precludes administration of oral antibiotics [32,38]. Therapy with an oral antibiotic should be initiated 24 hours later, provided the vomiting has resolved.

Vomiting that persists for more than 24 hours and vomiting that is associated with periorbital/orbital swelling and/or persistent headache should prompt consideration of orbital or intracranial complication. Additional evaluation is needed. (See "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Complications'.)

Treatment failure in outpatients — Treatment failure is defined by substantial worsening at any time after initiation of antibiotics or failure to improve after three days [39,40]. Treatment failure in children with ABRS who have no evidence of complications (table 3) is often caused by a pathogen resistant to initial antimicrobial therapy [32,38]. (See 'Microbiology' above.)

●Consider other causes of symptoms – Other causes of treatment failure include a noninfectious cause for symptoms (eg, foreign body, structural abnormality) or ABRS as the initial presentation of immune deficiency [32,38,61]. (See "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Differential diagnosis' and "Approach to the child with recurrent infections".)

●Changes to antibiotic therapy – For children with uncomplicated ABRS who are initially treated as outpatients and whose symptoms worsen substantially at any time or fail to improve after three days of initial antimicrobial treatment and in whom other causes of symptoms have been excluded by history or examination, we suggest broadening antimicrobial activity or switching to a different class of antibiotic (algorithm 1A-B).

We continue antibiotic therapy for seven days after the child becomes symptom free (ie, a minimum of 10 days) [38,62].

Our choices for the new regimen depend upon which antibiotic was used initially:

•Initial treatment with standard-dose amoxicillin-clavulanate or amoxicillin (standard or high-dose) – We switch to one of the following:

-Amoxicillin-clavulanate 90 mg/kg per day of the amoxicillin component orally in two divided doses (maximum daily dose 4 g); in the United States, the 600 mg amoxicillin/5 mL suspension or the 1000 mg extended-release tablet can be used for the appropriate clavulanate ratio

-Ceftriaxone 50 mg/kg per day IV or IM (maximum 4 g/day) for one to three days, followed by amoxicillin-clavulanate 90 mg/kg per day of the amoxicillin component

•Initial treatment with high-dose amoxicillin-clavulanate – We switch to one of the following:

-Cefpodoxime 10 mg/kg per day orally divided every 12 hours (maximum daily dose 400 mg/day)

-Cefdinir 14 mg/kg per day orally divided every 12 or 24 hours (maximum daily dose 600 mg/day)

-Levofloxacin 10 to 20 mg/kg per day orally divided every 12 or 24 hours (maximum daily dose 500 mg/day); levofloxacin should be reserved for cases in which there is no other safe and effective alternative [58-60] (see "Fluoroquinolones", section on 'Children')

•Initial treatment with cefpodoxime or cefdinir – We switch to either:

-Amoxicillin-clavulanate (depending on why a cephalosporin was started) 90 mg/kg per day of the amoxicillin component orally in two divided doses (maximum daily dose 4 g), or

-Levofloxacin 10 to 20 mg/kg per day orally divided every 12 or 24 hours; levofloxacin should be reserved for cases in which there is no other safe and effective alternative [58-60] (see "Fluoroquinolones", section on 'Children')

●Response to second therapy – Hospital admission for a trial of intravenous therapy and/or consultation with a specialist (eg, infectious disease, otolaryngology) is warranted for children with ABRS who fail to improve after the second therapy (algorithm 1A-B). (See 'Inpatient management' below and 'Indications for hospitalization' below.)

•For children with no contraindications to penicillins, we use:

-Ceftriaxone 50 mg/kg per day IV divided every 12 hours (maximum 4 g/day)

•For children with contraindications to penicillins, we use either:

-Levofloxacin 20 mg/kg per day IV divided every 12 to 24 hours (maximum 500 mg/day), or

-Meropenem 60 mg/kg per day divided every 8 hours (maximum 3 g/day)

For those who failed treatment with levofloxacin at 10 mg/kg per day orally, it is reasonable to try levofloxacin at 20 mg/kg per day IV. For those who failed treatment with oral levofloxacin 20 mg/kg per day, meropenem is appropriate.

In addition, imaging and/or sinus aspiration may be indicated to confirm the diagnosis, evaluate complications, and tailor therapy, particularly for children whose symptoms have not improved or have worsened after three days of initial antibiotics and another three days of the second agent. (See "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Complicated ABRS' and "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Microbiologic evaluation'.)

Symptomatic therapy

●Nasal obstruction/rhinorrhea in children without underlying allergic rhinitis – For symptomatic management of nasal obstruction and rhinorrhea in children with ABRS who do not have underlying allergic rhinitis, we suggest topical saline rather than decongestants, antihistamines, or intranasal glucocorticoids.

Although evidence of the efficacy of topical saline is limited [63-65], it is unlikely to be harmful or to impede recovery and is inexpensive. Saline nose drops, saline nasal sprays, and/or saline nasal irrigation may help in preventing crust formation and liquefying sinus secretions. In a small randomized trial, nasal saline irrigation improved symptoms, quality-of-life scores, and peak expiratory flow rates in children with acute sinusitis [65]. Additional trials are need to better establish the benefits of topical saline. Nasal irrigants should be prepared from sterile or bottled water; cases of amebic encephalitis associated with nasal irrigation prepared from tap water have been reported [66]. (See "Free-living amebas and Prototheca", section on 'Epidemiology'.)

The benefits of decongestants and antihistamines are unproven [63,67] and they may have adverse effects (eg, impaired sinus drainage, impaired delivery of antibiotics to the nasal mucosa). Although intranasal glucocorticoids theoretically may decrease inflammation of the mucous membranes, which contributes to obstruction of the ostia and impaired mucociliary clearance [68], the benefits demonstrated in randomized trials have been marginal and the trials have methodologic limitations (eg, varying inclusion criteria, inclusion of patients with and without allergies, varying outcome criteria) [38,69-72].

●Nasal obstruction/rhinorrhea in children with underlying allergic rhinitis – Children with ABRS and allergic rhinitis may benefit from antihistamines, decongestants, or intranasal glucocorticoids. The treatment of allergic rhinitis in children is discussed separately. (See "Pharmacotherapy of allergic rhinitis", section on 'Approach to specific patient groups'.)

●Severe headache or facial pain — Therapeutic sinus aspiration (figure 1) may be warranted for relief of severe headache or facial pain [73]. Sinus aspiration should be performed by a specialist. Indications for diagnostic sinus aspiration are discussed separately. (See "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Microbiologic evaluation'.)

INPATIENT MANAGEMENT

Indications for hospitalization — Indications for hospitalization and parenteral antibiotics in children with ABRS (table 1) include (see 'Inpatient management' above):

●Toxic appearance (eg, lethargic, poorly perfused, cardiorespiratory compromise)

●Complications or suspected complications (table 3), with the possible exception of preseptal cellulitis (patients older than one year with mild preseptal cellulitis [characterized by slight swelling about the eye such that the eye is open more than 50 percent] and no signs of toxicity may be treated as outpatients provided that follow-up the next day is ensured) (see "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Complications' and 'Complicated ABRS' below and "Preseptal cellulitis", section on 'Treatment')

●Treatment failure with outpatient therapy (ie, high-dose amoxicillin-clavulanate, third-generation cephalosporin, or levofloxacin) (see 'Treatment failure in outpatients' above)

Pretreatment evaluation — Consultation with an otolaryngologist for possible sinus aspiration (with Gram stain, aerobic and anaerobic culture, and antimicrobial susceptibility testing) is warranted for children hospitalized with complications of ABRS or failure of outpatient management [32,73]. Isolation of a pathogen and antimicrobial susceptibilities enable better targeting of antimicrobial therapy. (See "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Microbiologic evaluation'.)

For children who are hospitalized for toxic appearance without complications or suspected complications, sinus aspiration may be deferred pending a trial of intravenous therapy [38].

Although there is literature suggesting that endoscopically obtained cultures of the middle meatus may be a surrogate for sinus aspiration, endoscopically obtained cultures of the middle meatus may not reflect the true bacterial etiology in children suspected to have ABRS because the meatus is frequently colonized with S. pneumoniae, H. influenzae, and M. catarrhalis, even when children are asymptomatic [74].

Complicated ABRS — Sinus imaging with contrast-enhanced computed tomography (CT) should be performed in patients with symptoms or signs of intracranial or orbital complications (table 3). (See "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Complications'.)

The treatment of complicated sinusitis varies depending upon the complication and is discussed separately:

●Preseptal (periorbital) cellulitis (see "Preseptal cellulitis", section on 'Treatment')

●Postseptal complications of sinusitis (orbital cellulitis, orbital subperiosteal abscess, orbital abscess) are treated similarly; orbital subperiosteal abscess and orbital abscess may require surgical drainage in addition to antibiotic therapy (see "Orbital cellulitis", section on 'Treatment')

●Septic cavernous sinus thrombosis (see "Septic dural sinus thrombosis", section on 'Treatment')

●Meningitis (see "Bacterial meningitis in children older than one month: Treatment and prognosis")

●Osteomyelitis of the frontal bone associated with a subperiosteal abscess (Pott puffy tumor) (see "Hematogenous osteomyelitis in children: Management")

●Intracranial epidural or subdural abscess (see "Spinal epidural abscess", section on 'Management')

●Brain abscess (see "Treatment and prognosis of bacterial brain abscess")

Uncomplicated ABRS — Empiric therapy for children hospitalized with uncomplicated ABRS should provide activity against highly resistant S. pneumoniae, ampicillin-resistant H. influenzae, and ampicillin-resistant M. catarrhalis. The regimen should be adjusted based upon clinical response and culture results. (See 'Microbiology' above.)

We suggest initial empiric antibiotic therapy with one of the following agents (table 6) [32]:

●Ampicillin-sulbactam 200 to 400 mg/kg per day intravenously (IV) divided every six hours (maximum 8 g ampicillin component per day), or

●Ceftriaxone 50 mg/kg per day IV divided every 12 hours (maximum 4 g per day), or

●Levofloxacin 10 to 20 mg/kg per day IV divided every 12 to 24 hours (maximum 500 mg per day); levofloxacin should be reserved for cases in which there is no other safe and effective alternative [58,60] (see "Fluoroquinolones", section on 'Children')

These suggestions are based on in vitro susceptibilities. There are no studies comparing intravenous antibiotic regimens for the treatment of ABRS in children.

We continue antimicrobial therapy for a total of 10 days in patients whose symptoms improve after three days of parenteral therapy. We switch to oral antibiotics after the child shows definite signs of clinical improvement.

●Positive sinus aspirate culture – For children with a positive sinus aspirate culture, we choose an oral agent to which the isolate is susceptible.

●Negative sinus aspirate culture or no sinus aspirate culture obtained – For children in whom sinus aspirate cultures were not obtained or were negative, the choice of oral therapy varies with the reason for admission:

•For those who were admitted because of failure to respond to initial oral therapy with amoxicillin-clavulanate, we generally use either:

-Cefpodoxime 10 m/kg per day orally divided in two doses (maximum 400 mg/day), or

-Cefdinir 14 mg/kg per day orally divided in one or two doses (maximum 600 mg/day).

-For children who improved with parenteral ampicillin-sulbactam, amoxicillin-clavulanate 90 mg/kg per day of the amoxicillin component orally in two divided doses (maximum daily dose 4 g) for 10 days; in the United States, the 600 mg amoxicillin/5 mL suspension or the 1000 mg extended-release tablet can be used for the appropriate clavulanate ratio.

Levofloxacin is an alternative but should be reserved for cases in which there is no other safe and effective alternative (eg, in patients who have anaphylaxis with or are intolerant of beta-lactams) [58-60].

•For those who were admitted because of toxic appearance, we usually switch to amoxicillin-clavulanate:

-For children with no risk factors for resistance (table 5) – Amoxicillin-clavulanate 45 mg/kg per day of the amoxicillin component orally in two divided doses (maximum daily dose 1.75 g) for a total of 10 days.

-For children with risk factors for resistance – Amoxicillin-clavulanate 90 mg/kg per day of the amoxicillin component orally in two divided doses (maximum daily dose 4 g) for 10 days; in the United States, the 600 mg amoxicillin/5 mL suspension or the 1000 mg extended-release tablet can be used for the appropriate clavulanate ratio.

Treatment failure in inpatients — Treatment failure is defined by substantial worsening at any time or failure to improve after three days of antimicrobial therapy [39,40]. Causes of treatment failure in children with ABRS who are treated as inpatients include resistant pathogens, development of complications (table 3), noninfectious causes for symptoms, or ABRS as the initial presentation of immune deficiency [32,38,61]. (See 'Microbiology' above and "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Differential diagnosis' and "Approach to the child with recurrent infections".)

●Additional evaluation – Failure to improve or worsening in hospitalized children who are receiving empiric antibiotic therapy warrants additional evaluation, including [32]:

•Consideration of noninfectious causes (eg, foreign body, structural abnormality) or ABRS as the initial presentation of immune deficiency [32,38,61] (see "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Differential diagnosis' and "Approach to the child with recurrent infections")

•Contrast-enhanced CT imaging or magnetic resonance imaging to exclude orbital and intracranial complications (if not performed previously) (table 3)

•Quantitative sinus aspirate cultures if they were not obtained at the time of admission (see "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Microbiologic evaluation')

●Changes to antibiotic therapy – For children with ABRS in whom other causes of symptoms have been excluded by history or examination, we modify initial antimicrobial therapy:

•Pathogen isolated from sinus aspirate – Antimicrobial therapy should be modified according to results of sinus aspirate culture as soon as the results are available.

•No pathogen isolated or cultures not performed – For children with ABRS who fail to improve despite parenteral therapy with ampicillin-sulbactam, a third generation cephalosporin, or levofloxacin, and in whom no pathogen is isolated or sinus aspirate cultures are unavailable or contraindicated, the addition of vancomycin with or without metronidazole may be warranted [75]. Vancomycin provides activity against highly resistant S. pneumoniae and S. aureus; metronidazole provides activity against anaerobes.

-Vancomycin (table 7)

-Metronidazole 30 mg/kg per day IV divided every six hours (maximum 4 g/day)

●Response to escalated therapy – For patients who improve after changes to initial antimicrobial therapy, we continue antimicrobial therapy until they are free of symptoms for seven days (ie, a minimum of 10 days) [38,62].

For patients who fail to respond to changes to escalated antimicrobial therapy, consultation with an infectious disease specialist and/or otolaryngologist is suggested.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Acute rhinosinusitis".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or email these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient education" and the keyword[s] of interest.)

●Basics topic (see "Patient education: Sinusitis in children (The Basics)")

SUMMARY AND RECOMMENDATIONS

●Microbiology – Haemophilus influenzae (nontypeable), Streptococcus pneumoniae, and Moraxella catarrhalis are the predominant causes of uncomplicated acute bacterial rhinosinusitis (ABRS) in otherwise healthy children. (See 'Microbiology' above.)

●Outpatient management – We generally treat children with ABRS who are well-appearing and without complications or suspected complications (table 3) as outpatients. (See 'Outpatient management' above.)

•Empiric antibiotics – For children with uncomplicated ABRS (table 1), we suggest treatment with antimicrobial therapy rather than observation (Grade 2B). Improvement and resolution of symptoms are more likely with antibiotic therapy. (See 'When to initiate antibiotics' above.)

Although we usually initiate antimicrobial therapy at the time of presentation, an alternative is to offer children with ABRS and 10 days of symptoms that are neither severe nor worsening the options of:

-Empiric treatment after testing (performance of nasopharyngeal or nasal swab for presence of H. influenzae or S. pneumoniae) with plan to discontinue if negative

-Testing with treatment only if test is positive

-Watchful waiting with treatment if symptoms persist beyond three days

For initial treatment of uncomplicated ABRS in most children, we suggest amoxicillin-clavulanate rather than other oral antibiotics (algorithm 1A-B) (Grade 2B). We prefer amoxicillin-clavulanate because of its spectrum of activity, effectiveness, and safety. (See 'Empiric antibiotics' above.)

For children whose symptoms worsen substantially at any time or who fail to improve after three days of oral antibiotics, we broaden antimicrobial activity or switch to a different class (algorithm 1A-B and table 6). (See 'Treatment failure in outpatients' above.)

•Symptomatic management – For the management of nasal symptoms in children who do not have allergic rhinitis, we suggest topical saline rather than decongestants, antihistamines, or intranasal glucocorticoids (Grade 2C). Although evidence of benefit is limited, topical saline is inexpensive and unlikely to be harmful. (See 'Symptomatic therapy' above.)

The treatment of allergic rhinitis is discussed separately. (See "Pharmacotherapy of allergic rhinitis", section on 'Approach to specific patient groups'.)

●Inpatient management

•Indications for hospitalization – Indications for hospitalization and parenteral therapy include (see 'Indications for hospitalization' above):

-Toxic appearance (lethargic, poorly perfused, cardiorespiratory compromise)

-Complications or suspected complications (table 3); children older than one year with mild preseptal cellulitis are a possible exception

-Failure of outpatient therapy

•Complicated ABRS – For children hospitalized with complicated ABRS (table 3), we perform sinus imaging with contrast-enhanced CT in patients with symptoms or signs of intracranial or orbital complications if imaging was not previously performed. Additional management varies depending upon the complication. It is discussed separately. (See 'Complicated ABRS' above.)

•Uncomplicated ABRS – For children hospitalized with uncomplicated ABRS, we provide empiric therapy with activity against highly resistant S. pneumoniae, ampicillin-resistant H. influenzae, and ampicillin-resistant M. catarrhalis (table 6). We adjust the regimen based upon culture results (if available) and clinical response. (See 'Uncomplicated ABRS' above.)

For children whose symptoms worsen substantially at any time or who fail to improve after three days of intravenous antibiotics, additional evaluation is warranted, including evaluation for complications and quantitative sinus aspirate cultures if these studies were not obtained at the time of admission. (See 'Treatment failure in inpatients' above.)