Sinusitis: Diagnosis and Treatment

, Clinical Instructor in Medicine, Kansas University Medical Center, Kansas City, Kan.

Disclosures

Medscape General Medicine. 1997;1(2) 

In This Article

Diagnosis

A careful history looking for the subtle symptoms of sinusitis, (as reviewed in the section on Clinical Presentation), must always be the starting point for diagnosing sinusitis. The physical examination should involve assessment of mucosal pallor or inflammation and presence and character of secretions, as well as a comparison of these findings between the left and right nostril. Many patients with chronic sinusitis will have nasal exams that are not diagnostic and within normal limits.

Subsequently, in my practice, we favor a carefully-positioned Water's view sinus x-ray, performed on a machine equipped with a collimator for better focus. (The Water's view is a posterior-anterior radiograph taken with the neck extended to permit an unobstructed view of the maxillary sinuses. It is taken in an upright position to better identify fluid levels, if present.) In my view, radiographs should always be performed before initiating treatment for sinusitis, because of their utility in determining the appropriate management. However, a careful history and physical examination may suffice before initiating treatment when simple, acute sinusitis is suspected in primary care settings where radiograph studies are not easily available. Many chronic cases will be missed if clinical judgment alone, without radiographs, is used to diagnose.

It has been established that mucosal thickening >6mm establishes the likelihood of bacterial infection (>3mm in children).[13] Also, the demonstration on radiograph of complete opacification of a maxillary sinus often indicates that medical therapy, to be successful, may need to be prolonged considerably beyond the 10 days routinely required to "sterilize" the cavity. In an upright film, an air-fluid level is easily recognizable, and is thought to denote acute disease-- or an acute exacerbation of chronic sinusitis, when it coexists with mucosal thickening. Finally, the presence of unilateral disease on a radiograph may indicate the presence of an anatomical abnormality requiring further investigation.

Rhinoscopy. Flexible fiberoptic rhinoscopy is indicated when chronic sinusitis is suspected, and has proven useful to delineate the presence of nasal polyps (often hidden from anterior viewing), septal spurs, bifid turbinates and other anatomical disturbances, as well as in localizing the source of nasal mucopus. These indications are generally associated with chronic sinusitis; the procedure is not needed in uncomplicated acute sinusitis. Adequate decongestion of the nose with oxymetazoline followed by anesthesia with 4% topical lidocaine will permit painless examination, even of small children seated in the laps of their parents. In our clinic, an ENT exam chair with a headrest is used and the rhinolaryngoscope is attached to a video camera, permitting exams to be recorded, an invaluable patient-education tool (Fig. 3). Rigid rhinoscopes are preferred by some otolaryngologists, and are routinely used for endoscopic surgery.

Flexible fiberoptic rhinoscopy may be used to demonstrate nasal polyps , septal spurs, bifid turbinates and other anatomic disturbances, and to localize the source of nasal mucopus.

Computerized tomography. A significant number of patients with chronic sinusitis, especially involving ethmoid or sphenoid cells, can not be adequately diagnosed by plain films. CT scans done coronally without enhancement, and with 3 mm slices, will delineate specific foci of infection and show inflammatory ostiomeatal blockage clearly. Rhinoscopy and CT increase the potential sensitivity in the diagnosis of sinusitis, but plain films are often sufficient and likely to be more cost-effective in uncomplicated cases.

Other diagnostic aids. Nasal smears, if properly obtained from the mid-portion of the lower turbinate, may be helpful. The Rhinoprobe device (Arlington Scientific, Inc. Arlington, TX 76011) is most useful for this purpose. High levels of neutrophils with intracellular bacteria are highly suggestive of infection, even when a screening x-ray fails to reveal such signs. Also, the nasal smear may show large quantities of eosinophils, indicating the possibility of an underlying allergy, or of the less common non-allergic rhinitis with eosinophilia syndrome (NARES). NARES is more likely when there are coexisting polyps. Transillumination of the sinuses may be helpful occasionally, but is not reliable, and ultrasound examinations of the sinuses have not proven useful, and have therefore been abandoned by most specialists. Pfister and colleagues[14] studied A-mode ultrasound and compared it to CT scans as the "gold standard" in 19 patients with asthma being screened for sinus disease. They found it to have a sensitivity of 70%, but a specificity of only 22%. They concluded that "[it] does not allow sufficient evaluation of ...mucosal hyperplasia and is therefore not suitable for initial screening in these patients." In contrast, they found that plain radiographs have a specificity of 86.7% using CT scan as the gold standard.

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