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Sinusitis
Elizabeth K. Stanford, MD
Sinusitis affects 12% of adults and complicates 0.5% of viral upper respiratory infections. Symptoms that have been present for less than 1 month are indicative of acute sinusitis, while symptoms of longer duration reflect chronic sinusitis.
Pathophysiology
Factors that predispose to sinus infection include anatomic abnormalities, viral URIs, allergies, overuse of topical decongestants, asthma, and immune deficiencies.
Acute sinusitis is associated with the same bacteria as otitis media. Streptococcus pneumoniae, Hemophilus influenzae, and Moraxella catarrhalis are the most commonly encountered pathogens. Thirty five percent of H influenzae and 75% of M catarrhalis strains produce beta-lactamases, making them resistant to penicillin antibiotics.
Chronic sinusitis is associated with Staphylococcus aureus and anaerobes.
Clinical evaluation
If symptoms have lasted for less than 7 to 10 days and the patient is recovering, a self-limited viral URI is the most likely cause. However, worsening symptoms or symptoms that persist for more than 7 days are more likely to be caused by sinusitis.
Symptoms of acute sinusitis include facial pain or tenderness, nasal congestion, purulent nasal and postnasal discharge, headache, maxillary tooth pain, malodorous breath, fever, and eye swelling. Pain or pressure in the cheeks and deep nasal recesses is common.
High fever and signs of acute toxicity are unusual except in the most severe cases. Purulent drainage in the patient's nose or throat may sometimes be seen.
The nasal mucosa is often erythematous and swollen. The presence of mucopus in the external nares or posterior pharynx is highly suggestive of sinusitis. Facial tenderness, elicited by percussion, is an unreliable sign of sinusitis.
Laboratory evaluation
Imaging. Plain films are usually unnecessary for evaluating acute sinusitis because of the high cost and relative insensitivity.
CT scanning is useful if the diagnosis remains uncertain or if orbital or intracranial complications are suspected. CT scanning is nonspecific and may demonstrate sinus abnormalities in 87% of patients with colds.
MRI is useful when fungal infections or tumors are seriously considered.
Sinus aspiration is an invasive procedure, and is only indicated for complicated sinusitis, immunocompromise, failure to respond to multiple courses of empiric antibiotic therapy, or severe symptoms.
Cultures of nasal secretions correlate poorly with results of sinus aspiration.
Management of sinusitis
Antibiotic therapy for sinusitis
First-line agents
Amoxicillin ( Amoxil): Adults, 500 mg tid PO for 14 days. Children, 40 mg/kg/d in 3 divided doses.
Trimethoprim/sulfamethoxazole ( Bactrim, Septra): Adults, 1 DS tab (160/800 mg) bid. Children, 8/40 mg/kg/d bid.
Erythro mycin/sulfisoxazole ( Pediazole): Children, 50/150 mg/kg/d qid.
A 2-3 week course of therapy is recommended; however, if the patient is improved but still symptomatic at the end of the course, the medication should be continued for an additional 5 to 7 days after symptoms subside.
Broader-spectrum agents
If the initial response to antibiotics is unsatisfactory, beta-lactamase-producing bacteria are likely to be present, and broad-spectrum therapy is required.
Amoxicillin/clavulanate ( Augmentin): adults, 250 mg tid or 875 mg bid; children, 40 mg/kg/d in 3 divided doses.
Cefuroxime axetil ( Ceftin): adults, 250 mg bid; children, 125 mg bid.
Cefixime ( Suprax): adults, 200 mg bid; children, 8 mg/kg/d bid.
Cefpodoxime ( Vantin) 200 mg bid
Loracarbef ( Lorabid): 400 mg bid.
Azithromycin ( Zithromax): 500 mg as a single dose on day 1, then 250 mg qd.
Clarithromycin ( Biaxin): 500 mg bid.
Penicillin-resistant S. Pneumoniae result from bacterial alterations in penicillin-binding proteins. Highly resistant strains are resistant to penicillin, trimethoprim/sulfamethoxazole (TMP/SMX), and third-generation cephalosporins. The prevalence of multiple-drug resistant S. pneumoniae is 20-35%. High dose amoxicillin (80 mg/kg/d), or amoxicillin plus amoxicillin/clavulanate, or clindamycin are options.
Chronic sinusitis is commonly caused by anaerobic organisms. 3-4 weeks of therapy or longer is required.
Ancillary treatments
Steam and saline improves drainage of mucus. Spray saline (NaSal) or a bulb syringe with a saline solution (1 tsp of salt in 1 qt of warm water) may be used.
Decongestants
Topical or systemic decongestants may be used in acute or chronic sinusitis, including phenylephrine ( Neo-Synephrine) or oxymetazoline (Afrin) nasal drops or sprays.
Oral decongestants, such as phenylephrine or pseudoephedrine, are active in areas not reached by topical agents.