Acute sinusitis is defined pathologically as transient inflammation of the mucosal lining of the paranasal sinuses that lasts less than four weeks.

• Clinically, it is characterized by nasal congestion; rhinorrhea; facial pain; hyposmia; sneezing; and, if more severe, additional malaise and fever.

• Acute sinusitis affects 1 to 5 percent of the adult population in Europe each year.

In clinically, radiologically, or bacteriologically diagnosed acute sinusitis, corticosteroids (intranasal spray) may reduce symptoms compared with placebo.

In clinically diagnosed acute sinusitis, there is currently little evidence from randomized controlled trials (RCTs) to support the use of amoxicillin, co-amoxiclav (amoxicillin/clavulanate), or doxycycline over placebo in terms of clinical cure rate.

• We found no RCTs on the effects of cephalosporins or macrolides compared with placebo in clinically diagnosed acute sinusitis.

In persons with acute sinusitis that has been radiologically or bacteriologically confirmed as caused by a bacterial infection, antibiotics seem to be effective.

• Amoxicillin and co-amoxiclav improve early clinical cure rates, but are associated with adverse gastrointestinal effects.

• Cephalosporins and macrolides also seem to be as effective as amoxicillin, and have fewer adverse effects.

• We found insufficient evidence to judge the effectiveness of doxycycline.

• Long-term antibiotic regimens (six- to 10-day courses) do not seem more effective than short-term treatments (three- to five-day courses), but they seem to produce more adverse effects.

• We found insufficient evidence to draw a conclusion about which is the most effective dosage regimen for antibiotics.

• Caution: Since the last update of this review, the acute sinusitis indication for telithromycin has been withdrawn by the U.S. Food and Drug Administration because the risks/benefits ratio is no longer favorable (February 12, 2007).

We found no studies examining the effectiveness of antihistamines, decongestants, steam inhalation, or saline nasal washes for sinusitis diagnosed clinically, radiologically, or bacteriologically.

Definition

Acute sinusitis is defined pathologically as transient inflammation of the mucosal lining of the paranasal sinuses lasting less than four weeks. Clinically, it is characterized by nasal congestion; rhinorrhea; facial pain; hyposmia; sneezing; and, if more severe, by additional malaise and fever. The diagnosis is usually made clinically (on the basis of history and examination, but without radiological or bacteriological investigation). Clinically diagnosed acute sinusitis is less likely to be caused by bacterial infection than acute sinusitis confirmed by radiological or bacteriological investigation. In this review, we have excluded studies of children, persons with symptoms lasting longer than four weeks (chronic sinusitis), and persons with symptoms after facial trauma. We have made it clear in each section whether we are discussing clinically diagnosed acute sinusitis or acute sinusitis with clinical symptoms that have also been confirmed by bacteriological or radiological investigation, because the effects of treatment may be different in these groups.

Incidence/Prevalence

Each year in Europe, 1 to 5 percent of adults are diagnosed with acute sinusitis by their general physicians. Extrapolated to the British population, this is estimated to cause 6 million restricted working days per year. Most persons with acute sinusitis are assessed and treated in a primary care setting. The prevalence varies according to whether diagnosis is made on clinical grounds or on the basis of radiological or bacteriological investigation.

Etiology/Risk Factors

One systematic review (search date: 1998) reported that approximately 50 percent of persons with a clinical diagnosis of acute sinusitis have a bacterial sinus infection. The usual pathogens in acute bacterial sinusitis are Streptococcus pneumoniae and Haemophilus influenzae, with occasional infection with Moraxella catarrhalis. A preceding viral upper respiratory tract infection is often the trigger for acute bacterial sinusitis, with approximately 0.5 percent of common colds becoming complicated by the development of acute sinusitis.

Prognosis

One meta-analysis of RCTs found that up to two thirds of persons with acute sinusitis had spontaneous resolution of symptoms without active treatment. One nonsystematic review reported that persons with acute sinusitis are at risk of chronic sinusitis and irreversible damage to the normal mucociliary mucosal surface. One further nonsystematic review reported rare life-threatening complications, such as orbital cellulitis and meningitis, after acute sinusitis. However, we found no reliable data to measure these risks.

editor’s note: Xylometazoline is no longer available in the United States.

search date: August 2007.

Adapted with permission from Ah-See K. Sinusitis (acute). Clin Evid Handbook.