Tag Archives: ct scan of sinuses

How to diagnose acute sinusitis? Clinical criteria and investigations

Mostly patients of sinusitis can be benefitted without much investigation as diagnosis is mainly based on clinical criteria in patient who presents with persistent or severe upper respiratory symptoms.


Although sinus aspiration is the gold standard for the diagnosis of acute bacterial sinusitis, it is an invasive, time consuming, and potentially painful procedure that should only be performed by a specialist (Oto-rhino-laryngologist).  It is not recommended for the routine diagnosis of bacterial sinusitis.


Nasal endoscopy for proper visualization of nose and sinuses is important for appropriate management.


Sometimes if symptoms persist for longer duration further investigation may be required like examination of mucocilliary mechanism, allergic and immune status of patient and computerized tomography (CT scan) of sinuses.

  How sinusitis develops?–

 Acute sinusitis usually follows an upper respiratory tract infection.

Upper respiratory infection causes– over production of mucus and– impaires mucocilliary clearance (small hair like structure, cilia helps propel mucus out).

 This compounded with blockage of opening of sinuses (osteomeatal area or key area) by mucosal edema and associated structural deformity of nose (like DNS, spur) leads to stagnation of secretion.

 Blockage of sinus opening also impedes with ventilation of sinus cavity.

 Stagnation and poor ventilation causes growth of bacteria.

  Certain factors predisposes for sinusitis-allergy, structural defects like deviated nasal septum, spur, low immunity like in HIV, defects of ciliary mechanism like cystic fibrosis, kartagenar’s  syndrome, and immotile cilia syndrome.

 Diagnosis of sinusitis:–

 Diagnosis is usually based on proper history and thorough physical examination.

 Nasal endoscopy for proper visualization of nose and sinuses is important for appropriate management.


 Purulent discharge from nose

Pain/pressure sensation over face more on leaning forward.


Nasal blockage

Changes in taste/smell

Poor response to decongestant


Pressure sensation in the ear. 

Be prepared with bombarding with questions, you may feel useless or you may not want to answer especially if you are having sinus headache. But it helps your clinician to reach to the diagnosis.

 Examination of nose:

 Nose is inspected thoroughly with nasal speculum (a small metal instrument), with a good source of light focused inside your nose. Any discharge coming from sinuses opening or any structural deformity is looked for. 


Previously head mirror and Bulls lamp was used to focus light in to nasal cavity.

head mirrorhead mirror


Bulls lamp

Bulls lamp

Some use direct source of light attached to headlight by a cable.

Head light with light source
Head light with light source

 With advancement in technology many E.N.T. Specialist are using nasal endoscope attached to camera and monitor to see the nose and nasopharynx. Endoscopic assessment of nose guide therapy and at the same time accurate pus-swab can be obtained for bacteriological examination.

Clinically tenderness over specific point of sinuses is assessed.

 Laboratory test: 

Not of much value in acute sinusitis.

In cases not responding to treatment it may be done.

 Immune status of patient-HIV/chemotherapy

Allergy testing

Nasal cytology

Sweat chloride test for cystic fibrosis

Cilliary function test

 In refractory cases one should always think possibility of fungal sinusitis.


X-Rays of sinuses are not helpful in making diagnosis.

 CT scan- CT scan are generally not advised routinely. It is advised by otolaryngologist if surgery is anticipated (to evaluate the extent of sinusitis and guiding during surgery), infection is severe or there is risk of complication.

 MRI– MRI is not as effective as CT scan in evaluating sinusitis and is more costly. But when your ENT specialist is suspecting fungal sinusitis (a topic I will cover in my next blogs), want to differentiate sinusitis from tumor or there is intracranial complications.  

 Determination of causative organism: –

 It requires puncture, aspiration of mucopus and culture, but usually it is not done initially as it is invasive procedure. It is reserved for cases refractory to primary line of management.

  Further studies are required in the field and acute bacterial sinusitis is to be differentiated from viral rhinosinusitis and severe common cold. Further researches are required to develop noninvasive strategies to accurately diagnose acute bacterial sinusitis.