Acute rhinosinusitis in adults

Definitions

Acute rhinosinusitis is an inflammation of the paranasal sinuses and the nasal cavity lasting no longer than 4 weeks. It can range from acute viral rhinitis (the common cold) to acute bacterial rhinosinusitis. Fewer than 5 in 1,000 colds are followed by bacterial rhinosinusitis.

Diagnosis

Estimate the probability of acute bacterial rhinosinusitis based on history and physical examination. The best predictors include maxillary toothache, poor response to decongestants, patient report of colored nasal discharge, purulent secretions by exam, and abnormal transillumination.

Treatment

Prescribe antibiotic therapy based on benefits and risks. Benefits depend on the probability of bacterial infection and the severity of symptoms. Risks of antibiotics include allergic reaction, potential side effects, and promotion of bacterial resistance. Antibiotics have not been shown to decrease the risk of complication or progression to chronic rhinosinusitis. Symptoms resolve within two weeks without antibiotics in 70% of cases and with antibiotics in 85% of cases.

First line antibiotics for acute bacterial rhinosinusitis are amoxicillin and trimethoprim/sulfamethoxazole. They are superior to placebo and as effective as other agents that are more expensive, have greater risk of side effects, and/or should be reserved for more serious infections [A]. Use first-line alternatives (e.g., doxycycline, azithromycin) only for patients allergic to both first line drugs. The usual initial course of antibiotics should be 10 to 14 days. An exception is azithromycin (500 mg daily), which should be prescribed for 3 days.

For partial but incomplete resolution after an initial course of antibiotics, extend the duration of antibiotic therapy by an additional 7 to 10 days for a total of 3 weeks of antibiotics.

For minimal or no improvement with initial treatment, consider changing to an antibiotic with broader coverage, including resistant strains. Options include amoxicillin at high dose, amoxicillin/clavulanate, and levofloxacin. Avoid ciprofloxacin due to limited activity against Streptococcus pneumoniae. Do not use telithromycin because risks for hepatotoxicity, loss of consciousness, and visual disturbances appear to outweigh potential benefits for this indication.

Ancillary therapies for acute rhinosinusitis have little supporting data. Some studies examining treatments for viral upper respiratory infections have shown:

• Efficacy in symptom control: decongestants and anticholinergics, including "first-generation" antihistamines (diphenhydramine, chlorpheniramine, clemastine) [A].
• Possible efficacy: zinc gluconate lozenges, vitamin C, Echinacea extract, saline irrigation [conflicting or insufficient data].
• No significant benefit: guaifenesin (except possibly at high dose), saline spray, steam, "non-sedating" antihistamines (loratadine, fexofenadine, cetirizine).

For recurrent acute rhinosinusitis or acute rhinosinusitis superimposed on chronic rhinosinusitis, the addition of high dose nasal corticosteroids may decrease duration of symptoms and improve rate of clinical success [A]. However, this approach is inconvenient, has potential side effects, and significant cost.

Imaging

If symptoms of rhinosinusitis persist for more than three weeks despite antibiotics or recur more than three times per year, a sinus computed tomography (CT) scan should be performed while the patient is symptomatic to reassess diagnosis and determine need for referral [C, D]. CT scans provide much better definition than a plain sinus x-ray series. Plain sinus x-rays, therefore, are not recommended.

• New low dose CT scanners are becoming available with the advantage of radiation exposure of about 10% to 15% of a full sinus CT scan.
• A limited (coronal plan only) sinus CT scan provides excellent imaging detail with only 50% of the radiation exposure of a full (axial and coronal planes) sinus CT scan.
• At University of Michigan Health System the charge is $1,416 for any sinus CT scan (low dose, limited, or full).

Definitions:

Levels of evidence for the most significant recommendations:

1. Randomized controlled trials
2. Controlled trials, no randomization
3. Observational trials
4. Opinion of expert panel

CLINICAL ALGORITHM(S)

An algorithm is provided in the original guideline document for the diagnosis of acute bacterial rhinosinusitis.