The Centers for Disease Control and Prevention (CDC) assembled a panel of national health experts, including physicians with expertise in internal, family, emergency and infectious diseases medicine, to develop evidence-based guidelines for evaluating and treating adults with acute respiratory disease. The goal of the guidelines, which were compiled by the CDC and other members of the panel, is to provide physicians with practical strategies for limiting antibiotic use to patients who are most likely to benefit. The complete treatment guidelines were published in the March 20, 2001 issue of Annals of Internal Medicine, and can be viewed online at http://www.annals.org/issues/v134n6/full/200103200-00013.html.

Rhinosinusitis is one of the 10 most common diagnoses in ambulatory practice and is the fifth most common diagnosis for which an antibiotic is prescribed. Physicians tend to think of rhinosinusitis as an acute bacterial infection and prescribe an antibiotic for 85 to 98 percent of patients even though it is estimated that only 0.2 to 2 percent of viral upper respiratory tract infections in adults are complicated by bacterial rhinosinusitis.

Rhinosinusitis is usually caused by a secondary infection resulting from sinus ostia obstruction or impairment of mucous clearance mechanisms caused by uncomplicated viral upper respiratory tract infections. The infection will often resolve without antibiotic treatment, even if it is bacterial in origin. The recommendations in part III of the guidelines present an argument for a conservative approach to antibiotic use in patients with rhinosinusitislike symptoms.

Diagnosis

Overdiagnosis of acute bacterial rhinosinusitis is not surprising because specific clinical features that distinguish it from nonbacterial upper respiratory tract infection are lacking. Often, patients and physicians believe that antibiotics are necessary because symptoms have gone on for too long, but duration of illness does not reliably distinguish between viral and bacterial infections. The gold standard for diagnosis of bacterial rhinosinusitis is sinus puncture with aspiration of purulent secretions. This procedure is seldom performed in primary care because it is invasive and is usually indicated only for complicated cases or those that are resistant to treatment. There is no simple and accurate office-based test for acute bacterial sinusitis, so physicians must rely on clinical findings to make the diagnosis.

In the trials summarized by the panel, no single sign or symptom had strong diagnostic value, although certain combinations of signs and symptoms seemed more helpful. Presence of symptoms for at least seven days, persistent purulent nasal discharge with maxillary tooth or unilateral facial pain, unilateral sinus tenderness and worsening symptoms after initial improvement seem to predict a higher likelihood of bacterial infection. Patients who have symptoms for fewer than seven days are unlikely to have a bacterial infection. The absence of complete opacification, air-fluid level and mucosa thickening on sinus radiography has an estimated sensitivity of about 90 percent. It can be helpful in ruling out bacterial rhinosinusitis, but the test has limited value because of the high prevalence of abnormal findings.

Treatment

Even though antibiotics are statistically more effective than placebo in reducing or eliminating symptoms at 10 and 14 days, the degree of benefit is relatively small. Most patients who receive placebo improve without antibiotic therapy, so symptomatic treatment and reassurance are the preferred initial treatment strategy for patients with mild symptoms. As an alternative to antibiotic therapy, physicians can offer pain medications and decongestants to ease nasal symptoms and facial pain and promote mucous clearance. For those with severe symptoms, initial antibiotic therapy should be with narrow-spectrum agents, such as amoxicillin, doxycycline and trimethoprim-sulfamethoxazole. All patients should receive an explanation of the rationale for management and be educated about worsening signs and symptoms that should prompt them to contact a physician.

Recommendations

These recommendations are limited to the diagnosis and treatment of acute maxillary and ethmoid rhinosinusitis in immunocompetent adults.

• Sinus radiography and limited sinus computed tomography are not recommended for the diagnosis of uncomplicated rhinosinusitis because of the high prevalence of abnormal radiographic findings in patients with viral rhinosinusitis.

• Acute bacterial rhinosinusitis does not require antibiotic treatment, especially if symptoms are mild or moderate. Symptomatic treatment or reassurance is the preferred initial management strategy. Appropriate doses of analgesics, antipyretics and decongestants should be offered, as well as patient education about the chosen treatment strategy.

• Patients with severe or persistent moderate symptoms and specific findings of bacterial rhinosinusitis should be treated with antibiotics. Narrow-spectrum agents with activity against the most likely pathogens, Streptococcus pneumoniae and Haemophilus influenzae, are reasonable first-line agents. Physicians should also consider factors that predispose patients to antibiotic-resistant bacteria, such as contact with children in day care or recent antibiotic use.