Sinusitis presents a number of diagnostic and therapeutic problems to the clinician. The classic features of the disease—fever, purulent nasal discharge, facial pain and tenderness—may be absent. It is often difficult to differentiate a viral upper respiratory infection from a superimposed bacterial sinusitis requiring antimicrobial therapy. There are no simple diagnostic tests available to establish the diagnosis, and the sinus radiographs may be confusing at times. Laboratory confirmation of the etiologic agent is also difficult to obtain without an invasive procedure. Because the throat or nasal swab cultures are generally misleading in a patient with sinusitis (sinus aspirations are not routinely performed), empiric antimicrobial therapy is usually initiated.
Sinusitis is a common disorder, occurring from the first year of life. About 11.6 million office visits are made for sinusitis yearly in the United States. Infection occurs most often in the maxillary sinus and rarely in the sphenoid sinus. The opening of the maxillary sinus is located on the upper part of the medial wall of the sinus, and as a result, the maxillary sinus does not drain by gravity in the upright position. The close relationship of the sinuses to the orbits, frontal and maxillary bones, and intracranial structures easily explains the potentially life-threatening complications that can result from either contiguous spread or hematogenous dissemination of infection from the sinuses. Complications of sinusitis include orbital cellulitis, subperiosteal abscess, orbital abscess, frontal (Pott’s puffy tumor) and maxillary osteomyelitis, subdural abscess, cavernous sinus thrombosis, meningitis, and brain abscess. The most common complication is periorbital swelling resulting from impaired venous drainage, which can occur with maxillary or ethmoid sinusitis.
Obstruction of the sinus ostia by anatomic causes, such as a nasal foreign body or vascular congestion secondary to a viral upper respiratory infection, or by allergic rhinitis can result in an alteration of the local flora and sinusitis. Sinusitis can also occur when local host defenses are impaired, as in patients with the immotile cilia syndrome. About 10% of adult patients have maxillary sinusitis with a dental source—the extension of a periapical abscess of an upper tooth directly to the maxillary sinus. Sinusitis can be caused by diving into a pool or by barotrauma. In a hospitalized patient with a nasotracheal or nasogastric tube, sinusitis should be considered as a possible occult source of unexplained fever. One small series noted sinusitis in about 25% of patients who underwent nasotracheal intubation for 5 days or longer. In the majority of patients in whom sinusitis develops, however, a preceding viral upper respiratory infection or, less often, a history of allergic rhinitis can be elicited.
The etiologic agents involved in acute sinusitis are similar to those in acute otitis media. Aspiration of the maxillary sinuses has shown that Streptococcus pneumoniae and Haemophilus influenzae are responsible for just over half of the cases. The H. influenzae strains are usually nontypeable, and 17% to 68% produce b-lactamase. About 20% or more of the cases in children, depending on the cultural methods, are caused by Moraxella (Branhamella) catarrhalis, an organism that is almost always b-lactamase-positive. Other organisms recovered from the sinuses of patients with acute infection include anaerobes, Staphylococcus aureus, and Streptococcus pyogenes (group A). Viruses account for about 10% to 20% of the cases. Gram-negative rods, such as Pseudomonas species, are the most frequent cause of nosocomial sinusitis. Anaerobes are isolated more often in patients with associated dental disease and in those with chronic sinusitis. A variety of anaerobes, such as anaerobic streptococci and Bacteroides species, can be found in half of the patients with chronic sinusitis. Pseudomonas aeruginosa and H. influenzae are the predominant organisms found in patients with acute maxillary sinusitis and cystic fibrosis. The possibility of fungal infection caused by Mucor species, Aspergillus species, or Pseudoallescheria boydii should be considered when a diabetic patient, a renal transplant recipient, or patient with acute leukemia presents with acute illness, usually maxillary or ethmoid sinusitis. Rhinocerebral mucormycosis results from extension of the fungi from the sinuses to the orbit, meninges, and frontal lobes of the brain.
The presenting features of maxillary sinusitis can include nasal discharge, which is usually purulent; facial pain; impaired sense of smell; and sense of fullness of the sinus. Only half of children and adults with maxillary sinusitis will be febrile, but a nasal discharge is generally present. In children, a cough, nasal discharge, and fetid breath are frequently present. Facial pain and headache are major complaints in older children. Patients can have pus in the sinuses and still be asymptomatic. A clue to the diagnosis of acute sinusitis is an unusually severe or protracted “cold” (persisting beyond 10 days). Sphenoid sinusitis is frequently misdiagnosed and should be considered in patients with a severe headache, fever, purulent nasal discharge, and paresthesias of cranial nerve V. Facial tenderness, periorbital swelling, and pus on rhinoscopy may be present, but in the majority of patients, the physical examination is not helpful in establishing the diagnosis of acute sinusitis.
A variety of diagnostic tests are available to help confirm the diagnosis of sinusitis: transillumination, radiography, ultrasonography, computed axial tomography (CAT), magnetic resonance imaging (MRI), and sinus endoscopy. Routine sinus radiographs are obtained most often, and the presence of an air-fluid level, complete opacification, or 4 mm or more of mucosal thickening correlates with a positive sinus aspirate in 75% of patients. Sinus x-ray studies are of value in persons over 1 year of age, but findings are often abnormal in those under 1 year of age without a history to suggest acute sinusitis. CT is the noninvasive modality of choice to evaluate the sinuses. A limited CT scan (5-mm slices) of the sinuses is a cost-effective study comparable in price with plain sinus radiography. Sinus endoscopy is recommended for patients with recurrent acute and chronic sinusitis. Determination of the bacteriology of sinusitis requires that sinus secretions be obtained directly from the sinus by needle aspiration. Unfortunately, nose, throat, and nasopharyngeal cultures do not predict the etiology of the sinusitis well in comparison with sinus aspiration cultures. Indications for sinus aspiration are (a) nosocomial sinusitis, (b) sinusitis in an immunocompromised host, (c) sinusitis in a severely ill patient, and (d) failure of the sinus infection to respond to several courses of antimicrobial therapy. Aspiration of the maxillary sinus can be performed safely in patients 2 years of age or older. The presence of a normal sinus flora is controversial. One small study recovered both anaerobic and aerobic organisms by obtaining sinus aspirates from normal sinuses.
Sinusitis should be considered as a cause of unexplained fever in patients with acute leukemia or HIV disease. The clinical presentation is often subtle. Aspergillus is a frequent pathogen in patients with acute leukemia. Approximately 75% of patients with HIV disease have a diffuse sinus infection with a median of six sinuses affected. The etiology of the sinus disease in patients with HIV infection remains unclear. For patients with a presumed sinus infection who fail to respond to conventional antimicrobial therapy, consideration should be given to aspirating the sinus. If the aspirate is nondiagnostic, a mucosal biopsy is indicated. Further information from a prospective study is needed to define the etiology better and determine an appropriate treatment of sinusitis in patients with HIV infection.
Because sinus aspirates are not routinely performed, antimicrobial therapy of this disease is usually empirically based on the bacteriology from previous studies. The antimicrobial agents selected should be at least adequate for S. pneumoniae and H. influenzae. M. catarrhalis appears to have an increasing role in this disease. Ampicillin, amoxicillin, amoxicillin-clavulanic acid, azithromycin, cefaclor, cefuroxime axetil, cefprozil, ciprofloxacin, clarithromycin, doxycycline, levofloxacin, loracarbef, and trimethoprim-sulfamethoxazole (TMP-SMX) are acceptable and show comparable efficacy.
There is no antimicrobial agent of choice for the therapy of acute sinusitis. The presence of a penicillin allergy, the prevalence of penicillin-resistant H. influenzae and M. catarrhalis, the frequency and nature of adverse effects, and drug cost are important factors to consider. Amoxicillin appears to be the preferred drug to initiate treatment of a patient with acute sinusitis. Amoxicillin-clavulanic acid, azithromycin, cefaclor, cefprozil, cefuroxime axetil, ciprofloxacin, clarithromycin, doxycycline, levofloxacin, loracarbef, and TMP-SMX are suitable alternative therapeutic agents. TMP-SMX is ineffective in patients with group A streptococcal infections. The optimal duration of therapy is unknown, but 10 to 14 days is conventional for acute disease.
Although controlled studies are lacking, establishing drainage with topical or oral decongestants is important. The best decongestant is steam. Decongestants, however, inhibit ciliary motion, an important local defense mechanism. Antihistamines should be avoided; they tend to thicken sinus secretions and impair drainage. Topical corticosteroids help reduce edema and are useful for patients with allergic rhinitis and chronic sinusitis. Guaifenesin has a limited role in thinning secretions. Analgesics are indicated, and any underlying predisposing factors should be corrected. Irrigation and surgical drainage are usually reserved for patients who fail to respond to conventional therapy. It is reasonable to try an alternative antimicrobial agent, such as amoxicillin-clavulanic acid, azithromycin, cefaclor, cefuroxime axetil, clarithromycin, cefprozil, ciprofloxacin, doxycycline, levofloxacin, or loracarbef, if a patient fails to respond to a course of amoxicillin.
The optimal therapy for chronic sinusitis is unknown, but amoxicillin and clindamycin are reasonable drugs with which to initiate therapy. If the patient fails to respond to therapy, then other disorders, such as Wegener’s granulomatosis or neoplastic disease, should be investigated. (N.M.G.)
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Radiographic improvement lags the clinical course.
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Sinusitis is a cause of occult fever in intubated ICU patients.
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Classic description of neurologic complications of acute frontal sinusitis.
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Anaerobes were isolated in 88% of adults with chronic sinusitis.
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Orbital complications with vision loss may result from sinusitis.
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Aspergillus is the most common cause of fungal sinusitis. Noninvasive disease (e.g., allergy or mycetoma) must be distinguished from invasive disease.
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Results of nasal swab cultures correlated poorly with those of direct sinus aspirate cultures.
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A possible site for S. aureus infection in a patient with toxic shock syndrome.
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Classic article. Anaerobes are an important cause of chronic sinusitis.
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Criteria for clinical and microbiologic evaluation are presented.
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MRI or CT was more sensitive than plain radiography. Half of the patients had persistent or recurrent disease.
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Review. About 60% of cases of acute sinusitis are caused by bacteria; in 15% of cases, viruses are isolated.
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The presence of an air-fluid level on x-ray film correlates with a positive culture in 89% of patients; with opacity, the yield is 56%.
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S. pneumoniae and H. influenzae accounted for 64% of the isolates.
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In 90% of patients, the infection was polymicrobial. (For a discussion noting that the infection is often clinically obscure in the ICU setting, see also Caplan ES, Hoyt NJ. Nosocomial sinusitis. JAMA 1982;247:639.)
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A favorable outcome was noted in 85% of patients having endoscopic sinus surgery for infection.
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Isolated sphenoid sinus disease had an infectious etiology in 61% and was caused by a benign or malignant tumor in 29%. Cranial nerve defects were noted in 12% of infectious cases and 60% of neoplasms.
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Ketoacidotic diabetics are predisposed to rhinocerebral mucormycosis.
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Often unsuspected. An intense unilateral, frontal, or occipital headache occurs. Neurologic complications such as cavernous sinus thrombosis and meningitis can be life-threatening.
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CT scans are superior to plain radiographs in establishing the diagnosis.
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Sinusitis in HIV-infected children is most often subacute and recurrent, with nasal discharge and cough common. Fever is usually absent.
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Most cases of chronic sinusitis are caused by anaerobes.
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Subdural empyema is the most frequent complication of frontal sinusitis.
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Sinusitis occurred in more than one third of patients after an allogeneic bone marrow transplant.
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At the 7-year follow-up, most (98%) patients after endoscopic sinus surgery were improved and did not require further surgery.
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P. aeruginosa was isolated most commonly.
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Nosocomial sinusitis occurs in 18% to 32% of endotracheally intubated patients and is usually caused by gram-negative bacilli or is polymicrobial.
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In patients with mild acute maxillary sinusitis, amoxicillin was not better than placebo in improving the outcome of the disease.
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Chronic sinusitis caused by infection is uncommon in children; persistent nasal symptoms are often caused by allergy.
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Classic study in children. Cough and nasal symptoms occur most often. Only half of children had fever initially.
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Similar clinical presentation (nasal discharge, cough), etiology, and radiographic findings as in acute disease.
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Approximately 80% cure rates with amoxicillin or cefaclor when 40 mg/kg per day was administered in three divided doses.
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Best predictors of sinusitis include maxillary toothache, abnormal transillumination, poor response to nasal decongestants, colored nasal discharge, and mucopurulence on examination.
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A 3-day course of TMP-SMX plus oxymetazoline was as effective as a 10-day course of the same drug in patients with mild sinusitis.
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Sinusitis is often (25%) asymptomatic in patients with HIV infection.