Rhinosinusitis is an extremely common condition. Nearly 1 in 7 people is diagnosed with a sinus infection each year. Although sinus infections are the fifth leading reason for antibiotic prescriptions, 90% to 98% of cases are caused by viruses, which are not affected by antibiotics. The inappropriate use of antibacterials for such viral infections fosters the development of antimicrobial resistance and should be avoided.
Earlier this year, the Infectious Diseases Society of America (IDSA) published a guideline for acute bacterial rhinosinusitis (ABRS) for adults and children, the first developed by IDSA on this topic.1 The IDSA guideline uses the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system, which is designed to more clearly assess the quality of evidence and strength of recommendations. Summarized below are several of the recommendations in this update (specific recommendations are graded as to the strength of recommendation [weak or strong] and the level of evidence [very low, low, moderate, or strong]).
Which clinical presentations best identify patients with acute bacterial versus viral rhinosinusitis?
Recommendations: The following clinical presentations (any of 3) are recommended for identifying patients with acute bacterial versus viral rhinosinusitis:
- onset with persistent symptoms or signs compatible with acute rhinosinusitis, lasting for 10 days without any evidence of clinical improvement (strong, low-moderate);
- onset with severe symptoms or signs of high fever and purulent nasal discharge or facial pain lasting for at least 3 to 4 consecutive days at the beginning of illness (strong, low-moderate);
- onset with worsening symptoms or signs characterized by the new onset of fever, headache, or increase in nasal discharge following a typical viral upper respiratory tract infection that lasted 5 to 6 days and were initially improving (“double-sickening”) (strong, low-moderate).
Some estimate that as much as 25% of all oral antimicrobial use in adults is for “sinusitis,” and it is clear that most of this is unwarranted because most cases are viral in etiology. Indeed, differentiation of viral (which is overwhelmingly more common) from bacterial etiology is the most significant challenge to clinicians regarding management of sinusitis. Although most clinical cases can be judged to be viral based on clinical manifestations, I acknowledge that several cases are gray. The best study to evaluate the timing of symptoms found that the 10-day criterion of persistent symptoms identified 60% of bacterial etiology on the basis of sinus puncture cultures.2 The current guideline recommends the adoption of characteristic patterns of clinical presentations for the clinical diagnosis of ABRS, taking into account not only the duration of respiratory symptoms but also the severity of illness, temporal progression, and classic double-sickening in the clinical course to differentiate bacterial from acute viral rhinosinusitis. These recommendations are intended to improve the likelihood of separating acute bacterial from viral rhinosinusitis. Although these clinical criteria do not definitely differentiate viral from bacterial, they do serve as a useful guidance to clinicians to assist in the decision regarding use of antimicrobials.
Should amoxicillin versus amoxicillin/clavulanate be used for initial empiric antimicrobial therapy of ABRS in children?
Recommendation: Amoxicillin/clavulanate rather than amoxicillin alone is recommended as empiric antimicrobial therapy for ABRS in children (strong, moderate).
Should amoxicillin versus amoxicillin/clavulanate be used for initial empiric antimicrobial therapy of ABRS in adults?
Recommendation: Amoxicillin/clavulanate rather than amoxicillin alone is recommended as empiric antimicrobial therapy for ABRS in adults (weak, low).
The recommendation of amoxicillin/clavulanate rather than amoxicillin for first-line therapy is a major change from prior consensus recommendations. This recommendation for adults is primarily based on in vitro data and awareness of trends indicating an increasing rate of Haemophilus influenzae etiology as a result of use of the conjugate pneumococcal vaccine in pediatrics that has significantly reduced transmission of Streptococcus pneumoniae to adults. However, the panel acknowledges this is more costly and may be associated with increase diarrhea, but justifies this on the basis that the addition of clavulanate to amoxicillin substantially improves the coverage for ampicillin-resistant H. influenzae and Moraxella catarrhalis in ABRS.
When is high-dose amoxicillin/clavulanate recommended during initial empiric antimicrobial therapy for ABRS in children or adults?
Recommendation: “High-dose” (2 g orally twice daily or 90 mg/kg per day orally twice daily) amoxicillin/clavulanate is recommended for children and adults with ABRS from geographic regions with high endemic rates (>10%) of invasive penicillin-nonsusceptible S. pneumoniae, those with severe infection (eg, evidence of systemic toxicity with fever of 39°C [102°F] and threat of suppurative complications), attendance at day care, younger than 2 years or older than 65 years, recent hospitalization, antibiotic use within the past month, or those who are immunocompromised (weak, moderate).
Should a respiratory fluoroquinolone versus a β-lactam agent be used as first-line agent for the initial empiric antimicrobial therapy of ABRS?
Recommendation: A β-lactam agent (amoxicillin/clavulanate) rather than a respiratory fluoroquinolone is recommended for initial empiric antimicrobial therapy of ABRS (weak, moderate).
In a meta-analysis of 8 randomized clinical trials, respiratory fluoroquinolones conferred no benefit over β-lactam antibiotics in the treatment of ABRS.3 The comparator agents in these trials were amoxicillin/clavulanate in 5, cefuroxime in 2, and cefdinir in 1 patient. At present, respiratory fluoroquinolones should be reserved for those who have failed to respond to first-line agents, those with a history of penicillin allergy, and as second-line therapy for patients at risk for resistant S. pneumoniae infection. This recommendation places a relatively high value on limiting the development of antibiotic resistance and resource use.
Which antimicrobial regimens are recommended for the empiric treatment of ABRS in adults and children with a history of penicillin allergy?
- ○ Either doxycycline (not suitable for children) or a respiratory fluoroquinolone (levofloxacin or moxifloxacin) is recommended as an alternative agent for empiric antimicrobial therapy in adults who are allergic to penicillin (strong, moderate).
- ○ Levofloxacin is recommended for children with a history of type I hypersensitivity to penicillin; combination therapy with clindamycin plus a third-generation oral cephalosporin (cefixime or cefpodoxime) is recommended in children with a history of non–type I hypersensitivity to penicillin (weak,
Surveillance of recent respiratory isolates in the United States indicates a variable but significant increase in penicillin-intermediate and macrolide or trimethoprim/sulfamethoxazole–resistant S. pneumoniae and beta-lactamase–producing H. influenzae Accordingly, antimicrobial agents previously recommended as an alternative to amoxicillin or amoxicillin/clavulanate, such as macrolides, trimethoprim/sulfamethoxazole, or second- or third-generation oral cephalosporins, can no longer be recommended.
Available clinical as well as microbiological and pharmacokinetics/pharmacodynamics data do support the use of doxycycline as an alternative to amoxicillin/clavulanate for empiric antimicrobial therapy of ABRS in adults.
Should empiric antimicrobial therapy for ABRS be administered for 5 to 7 days versus 10 to 14 days?
Recommendations: The recommended duration of therapy for uncomplicated ABRS in adults is 5 to 7 days (weak, low-moderate). In children with ABRS, the longer treatment duration of 10 to 14 days is still recommended (weak, low-moderate).
A recent meta-analysis by Falagas et al4 examined the efficacy and safety of short versus longer courses of antimicrobial therapy for adults with ABRS enrolled in 12 randomized controlled trials. No statistical difference in efficacy was noted between short-course (3–7 days) versus long-course (6–10 days) antibiotic therapy. Data in pediatric patients, however, are inconclusive because the efficacy of shorter courses of therapy has not been specifically studied in a rigorous randomized fashion.
Is saline irrigation of the nasal sinuses of benefit as adjunctive therapy in patients with ABRS?
Recommendation: Intranasal saline irrigation with either physiologic or hypertonic saline is recommended as an adjunctive treatment in adults with ABRS (weak, low-moderate).
A recent Cochrane review evaluated the efficacy of saline nasal irrigations in treating acute upper respiratory tract infections including acute rhinosinusitis.5 Three randomized controlled trials (total of 618 participants) were included for analysis, and various nasal symptom scores were assessed. Although significant improvements were observed in some symptom scores (nasal secretion, nasal patency, and overall health status), these changes were relatively minor. The authors concluded that the trials were too small and had too high a risk of trial bias to be confident that the benefits were meaningful. Nevertheless, there was a trend toward reduced antibiotic use in one study as well as a significant reduction in time lost from work. Anectodally, I have found this to be beneficial when experiencing viral rhinosinusitis. It has been postulated that saline irrigation improves nasal symptoms by enhancing mucociliary function, decreasing mucosal edema, mechanically clearing inspissated mucus, and decreasing inflammatory mediators.
Are intranasal corticosteroids recommended as an adjunct to antimicrobial therapy in patients with ABRS?
Recommendation: Intranasal corticosteroids are recommended as an adjunct to antibiotics in the empiric treatment of ABRS, primarily in patients with a history of allergic rhinitis (weak, moderate).
Should topical or oral decongestants or antihistamines be used as adjunctive therapy in patients with ABRS?
Recommendation: Neither topical nor oral decongestants and/or antihistamines are recommended as adjunctive treatment in patients with ABRS (strong, low-moderate).
Despite the common use of decongestants and antihistamines in patients with ABRS, there is scant evidence to support that they hasten recovery. Although patients may subjectively feel improvement in nasal airway patency, objective rhinometric findings do not support this impression. In a study that evaluated topical oxymetazoline instilled in one nasal cavity and placebo in the other of rabbits, histological sections of the maxillary sinus mucosa revealed significantly more inflammatory changes in the oxymetazoline-treated side than in the placebo-treated side.6 The recommendation against the use of decongestants or antihistamines as adjunctive therapy in ABRS places a relatively high value on avoiding adverse effects from these agents and a relatively low value on the incremental improvement of symptoms. These agents may still provide symptom relief in some patients with acute viral rhinosinusitis when antimicrobial therapy is not indicated.
Other recommendations included in the guideline address the topics of the nonresponsive patient and when to refer to a specialist.