From the Guidelines
Diagnosing sinusitis typically doesn't require extensive testing for most cases, and a physical examination is often sufficient for uncomplicated cases with typical symptoms. For uncomplicated cases with typical symptoms (facial pain/pressure, nasal congestion, thick discharge, reduced sense of smell), a healthcare provider will perform a physical examination, focusing on the sinuses, nose, and throat, and this examination is often sufficient 1. If symptoms are severe, persistent beyond 10 days, or recurrent, additional tests may be ordered, such as:
- Nasal endoscopy to visualize the sinuses
- Imaging studies, like a CT scan, to provide detailed images of sinus structures
- Cultures of nasal secretions to identify specific bacteria causing infection
- Allergy testing if allergies are suspected as contributing factors MRI scans are rarely needed but may be used if complications or unusual causes are suspected 1. The American College of Radiology recommends that imaging studies are not necessary for uncomplicated acute sinusitis, but may be recommended for persistent, recurrent, or chronic sinusitis, or when there is concern for orbital or intracranial complications 1. In cases where complications are suspected, such as orbital or intracranial involvement, CT or MRI of the head and paranasal sinuses with IV contrast is recommended, and CTA or MRA/MRV may be complementary in cases with suspected vascular complications 1. Overall, the diagnosis of sinusitis is based on a combination of clinical presentation, physical examination, and, when necessary, additional testing to confirm the diagnosis and guide treatment.
From the Research
Diagnostic Tests for Sinusitis
The diagnosis of sinusitis relies heavily on medical history and physical examination, including nasal endoscopy 2. The following tests may be used to confirm the diagnosis and evaluate the extent of sinus involvement:
- Nasal cytologic studies
- Ultrasound studies
- Flexible or rigid nasal endoscopes
- Imaging tests such as radiology and computed tomography (CT) scans 3
- Transillumination, which can be useful in experienced hands, but only negative findings are reliable 4
- Radiography, which is not necessary when the likelihood of acute sinusitis is high or low, but can be useful when the diagnosis is uncertain 4
Specific Tests for Acute Sinusitis
For acute sinusitis, the following clinical findings are the best predictors of the condition:
- Maxillary toothache
- Poor response to decongestants
- History of colored nasal discharge
- Purulent nasal secretion
- Abnormal transillumination result 4
Tests for Chronic Sinusitis
In chronic sinusitis, the diagnosis can be made based on a careful history and physical examination, with radiography reserved for confirmation of clinical impression or documentation of disease 5. Fiberoptic rhinoscopy may be used as an adjunct in adults, but its clinical usefulness in children needs further study 5. CT scans can be used to evaluate the extent of sinus involvement and identify possible anatomic abnormalities 2.