Background
An expert panel from the Infectious Diseases Society of America recently published an evidence-based guideline for the diagnosis and management of acute bacterial rhinosinusitis (ABRS).
Conclusions
Sinusitis is one of the most common causes for medical visits. In a 2008 national survey, 13.4% of adults aged 18 years and older reported a diagnosis of sinusitis within the past year; increased rates were reported in persons 45-74 years old and in women. The incidence of sinusitis in adults is estimated to be two to three episodes annually.
A viral [common cold or URI] agent is the cause of 90%-98% of acute rhinosinusitis; bacterial infection is uncommon. Secondary bacterial sinusitis following a viral illness is estimated to occur in only 0.5%-2% of adult cases. Yet, a survey of outpatient prescribing for URI found that antibiotics were prescribed in more than 80% of patients with a diagnosis of sinusitis, making sinusitis the fifth-leading reason for an antibiotic prescription in ambulatory settings.
Dr. Abhishek Agarwal
Clinical presentations that suggest a bacterial etiology include persistent symptoms for more than 10 days without improvement; severe signs or symptoms [fever higher than 102° F, purulent nasal discharge or facial pain lasting at least 3 consecutive days from the onset of the illness]; or worsening symptoms or signs within 5-10 days after initial improvement (or "double sickening").
Since the introduction of conjugate pneumococcal vaccines, the prevalence of Haemophilus influenzae and the proportion of beta-lactamase-producing H. influenzae have increased, as has the prevalence of beta-lactamase-producing Moraxella catarrhalis. These organisms are routinely resistant to amoxicillin but commonly respond to amoxicillin-clavulanate. A recent study using sinus puncture–based cultures found Streptococcus pneumoniae (38%), H. influenzae (36%), and M. catarrhalis (16%) as the most frequent bacterial isolates in patients with ABRS.
Standard-dose amoxicillin-clavulanate is inadequate for treatment of penicillin-nonsusceptible (PNS) S. pneumoniae and the (much less common) ampicillin-resistant beta-lactamase-negative H. influenzae. In these isolates, resistance is due to a mutation in penicillin-binding protein, which can be overcome by higher doses of amoxicillin but not by the addition of a beta-lactamase inhibitor. Patients with increased risk of PNS S. pneumoniae include those younger than 2 years or older than 65 years, who attend day care, who have been hospitalized within the past 5 days, and who have been treated with antibiotics within the past month. The frequency of PNS S. pneumoniae ranges from 9% in the Northwest to 25% in the Southeast.
Macrolide resistance is present in about 30% of pneumococci. Both S. pneumoniae and H. influenzae also have high rates of resistance (about 30%-40%) to trimethoprim-sulfamethoxazole.
Implementation
Antibiotics should not be prescribed for patients who do not have symptoms suggestive of ABRS, that is, persons without persistent symptoms for 10 days or longer without improvement; severe symptoms or signs; or "double sickening."
Amoxicillin-clavulanate is the recommended empiric first choice for most adults and children who have a clinical syndrome consistent with ABRS. A treatment course of 5-7 days is recommended for adults and 10-14 days for children. Doxycycline is a reasonable alternative empiric antibiotic in adults. Prompt treatment can shorten the illness, improve quality of life, prevent recurrence, and reduce complications
Fluoroquinolones should not routinely be used for initial empiric treatment of sinusitis.
Adults living in regions with local rates of invasive PNS S. pneumonia more than 10%, immune-compromised patients, and those with severe infection (fever higher than 102° F, systemic toxicity, or at risk for suppurative complications) are at increased risk for ABRS due to resistant organisms. These adults should be treated with ‘‘high-dose’’ amoxicillin-clavulanate (90 mg/kg of the amoxicillin component, up to a maximum of 2 g twice daily).
Doxycycline or a respiratory fluoroquinolone [levofloxacin or moxifloxacin] is recommended for treatment of sinusitis in patients with penicillin allergy or those who fail to respond to first-line treatment.
Neither macrolides, trimethoprim-sulfamethoxazole, nor [second- or third-generation] cephalosporins are recommended for empiric therapy of ABRS due to the resistance patterns of common organisms causing ABRS.
S. aureus is a potential pathogen in ABRS, but routine empiric treatment for S. aureus or MRSA is not recommended.
Adjunctive treatment of ABRS with intranasal [isotonic or hypertonic] saline nasal irrigation and/or intranasal corticosteroids is recommended based on low- to moderate-quality evidence.
Intravenous ampicillin-sulbactam, a respiratory fluoroquinolone, or a third-generation cephalosporin can be chosen for severe infections requiring hospitalization.
Strong evidence supports the recommendation against using adjunctive topical or oral antihistamines and/or decongestants. While these medications may subjectively improve nasal airway patency, their associated adverse effects likely outweigh their minor benefits.
Patients who have deterioration in symptoms after 2-3 days of initial antibiotics, or who fail to improve after 3-5 days of therapy, should be changed to a different antimicrobial agent and the possibility of resistant bacteria, a noninfectious cause for symptoms, a structural abnormality, or other causes of treatment failure should be considered.