What is the diagnostic workup for sinusitis?

From the Guidelines

The workup for sinusitis should begin with a thorough history and physical examination, focusing on symptoms like facial pain/pressure, nasal congestion, purulent drainage, and decreased sense of smell, as recommended by the most recent guidelines 1.

Key Symptoms and Signs

• Symptoms suggestive of acute sinusitis include nasal congestion, purulent rhinorrhea, postnasal drainage, facial or dental pain, headache, and cough, frequently with a more severe nocturnal component 1.
• Any patient with orbital swelling or pain, swelling of the forehead, and/or diplopia should be urgently scheduled for evaluation 1.
• Children with acute sinusitis might also exhibit increased irritability and vomiting occurring in association with gagging on mucus, prolonged cough, or both 1.

Diagnostic Approach

• For uncomplicated acute sinusitis, diagnostic imaging is generally unnecessary, as stated in the 2015 clinical practice guideline update 1.
• However, if symptoms persist beyond 10 days, worsen after initial improvement, or are severe (high fever, purulent discharge, facial pain), further evaluation is warranted 1.
• Nasal endoscopy can help visualize purulent drainage and assess for anatomic abnormalities, and CT scanning is the imaging modality of choice when needed, particularly for evaluating chronic sinusitis or complications 1.
• Laboratory tests are typically not required unless complications are suspected, and for chronic sinusitis, allergy testing may be beneficial to identify contributing factors 1.

Treatment

• Treatment typically begins with saline irrigation and intranasal corticosteroids (such as fluticasone 50mcg 1-2 sprays per nostril daily or mometasone 50mcg 2 sprays per nostril daily) 1.
• For bacterial sinusitis, amoxicillin-clavulanate (875/125mg twice daily for 5-7 days) is the first-line antibiotic, and in penicillin-allergic patients, doxycycline (100mg twice daily) or a respiratory fluoroquinolone like levofloxacin (750mg daily) can be used 1.
• This stepwise approach allows for appropriate management while minimizing unnecessary testing and antibiotic use, which is important given the high rate of viral etiology in acute sinusitis cases 1.

From the Research

Sinusitis Workup

• The workup for sinusitis is designed to detect both the presence and extent of any disease in the paranasal sinus cavities 2
• Clinical diagnosis can usually be made from the patient's history and findings on physical examination only 3
• Five clinical findings comprising 3 symptoms (maxillary toothache, poor response to decongestants and a history of coloured nasal discharge) and 2 signs (purulent nasal secretion and abnormal transillumination result) are the best predictors of acute bacterial sinusitis 3
• Uncomplicated sinusitis does not require radiologic imagery, however, when symptoms are recurrent or refractory despite adequate treatment, further diagnostic evaluations may be indicated 4
• Plain radiography has a limited role in the management of sinusitis, although air-fluid levels and complete opacification of a sinus are more specific for sinusitis, they are only seen in 60 percent of cases 4
• Noncontrast coronal computed tomographic (CT) images can define the nasal anatomy much more precisely, and mucosal thickening, polyps, and other sinus abnormalities can be seen in 40 percent of symptomatic adults 4
• Use of CT is typically reserved for difficult cases or to define anatomy prior to sinus surgery 4
• Magnetic resonance imaging (MRI) cannot define bony anatomy as well as CT, and is only used to differentiate soft-tissue structures, such as in cases of suspected fungal infection or neoplasm 4
• Adjunctive tests in selected cases include nasal cytologic studies, ultrasound studies, and the use of flexible or rigid nasal endoscopes, in addition to imaging tests such as radiology and computed tomography 2
• Referral will occasionally be needed in unusual or complicated cases, and immunocompromised persons and smokers are at increased risk for serious sinusitis complications 4

Diagnostic Criteria

• A constellation of nonspecific symptoms such as facial pressure, headache, nasal obstruction, and drainage may occur in chronic sinusitis 2
• Physical examination is important to exclude anatomic causes of symptoms, and a negative physical examination does not rule out the diagnosis 2
• Transillumination is a useful technique in the hands of experienced personnel, but only negative findings are useful 3
• Radiography is not warranted when the likelihood of acute sinusitis is high or low but is useful when the diagnosis is in doubt 3

Management Strategies

• First-line therapy should be a 10-day course of amoxicillin (trimethoprim-sulfamethoxazole should be given to patients allergic to penicillin) 3
• A decongestant may also be used as part of the treatment regimen 3
• Patients allergic to amoxicillin and those not responding to first-line therapy should be switched to a second-line agent 3
• Patients with recurrent episodes of acute sinusitis who have been assessed and found not to have anatomic anomalies may also benefit from second-line therapy 3