Anything that causes a swelling in the nose—an infection, an allergic reaction, or an inflammatory reaction to a chemical to which you may get exposed--can affect your sinuses/ also abrupt pressure changes (air planes, diving) or dental extractions or infections.
This result in
a-Inflammation and edema of mucous membranes lining the sinuses cause obstruction .
b-This provides for an opportunistic bacterial invasion .
C- Postnasal drainage causes obstruction of nasal passages and an inflamed throat .
D-If the sinus orifices are blocked by swollen mucosal lining, the pus cannot enter the nose and builds up pressure inside the sinus cavities.
E-Air trapped within a blocked sinus, along with pus or other secretions may cause pressure on the sinus wall that can cause the intense pain of a sinus attack . Similarly, when air is prevented from entering a paranasal sinus by a swollen membrane at the opening, a vacuum can be created that also causes pain
A- Most cases of acute sinusitis start with a common cold (acute rhinitis) , which is caused by a virus. Colds can inflame your sinuses (damage to cells) and cause symptoms of sinusitis. Both the cold and the sinus inflammation usually go away without treatment within 2 weeks. However, In about 0.5-2% of cases, viral sinusitis can progress to acute bacterial sinusitis
The most common culprits in acute viral rhinosinusitis are rhinovirus , influenza virus , and parainfluenza virus .
The inflammation caused by the cold results in swelling of the mucous membranes (linings) of your sinuses, trapping air and mucus behind the narrowed sinus openings. When mucus stays inside your sinuses and is unable to drain into your nose, it can become the source of nutrients for bacteria, which then can multiply.
B- People who have allergies or other chronic problems that affect the nose are also prone to episodes of acute sinusitis. Chronic nasal problems cause the nasal membranes to swell and the sinus passages to become blocked. The normally harmless bacteria in your nose and throat again lead to acute sinusitis.
C- In general, people who have reduced immune function , such as those with primary immune deficiencys or HIV infection, or abnormalities in mucus secretion or mucus movement, such as those with cystic fibrosis , are more likely to suffer from sinusitis
D- mechanical obstruction as seen secondary to foreign bodies , intranasal cocaine use
E- Fungal infections very rarely cause acute sinusitis because the human body has a natural resistance to fungi . However, in people whose immune systems are not functioning properly, fungi can cause acute sinusitis.
A-In chronic sinusitis, the membranes of both the paranasal sinuses and the nose are thickened because they are constantly inflamed . Most experts now use the term chronic rhinosinusitis to describe this condition.
B- nasal polyps . (Polyps are grape-size growths of the sinus membranes that protrude into the sinuses or into the nasal passages,more commonly seen in patients with aspirin sensitivity and asthma , results from a localized allergic hyperresponsivity to bacterial endotoxins Polyps make it even more difficult for the sinuses to drain and for air to pass through the nose
D- An allergic reaction to certain fungi may be responsible for some cases of chronic rhinosinusitis; this condition is called allergic fungal sinusitis. However, at least half of all people with chronic rhinosinusitis do not have allergies/ or exaggerated immune response to fungi
E- Acute bacterial sinusitis that does not completely resolve can progress to chronic sinusitis, the infecting organisms vary, and a higher incidence of anaerobic organisms is seen (eg, Bacteroides , Peptostreptococcus , and Fusobacterium species
- Chronic nasal discharge, obstruction, and low-grade discomfort across the bridge of the nose - Pain worse in the late morning or when wearing glasses - Chronic sore throat and bad breath - Usually recurs in other sinuses
4-ENT can directly visualize the nasal passages and the OMC (passage into the sinuses) with a nasopharyngoscope . This is a fiberoptic, flexible tube that is insertable through the nose and enables the doctor to view the passageways and see if the OMC is open and draining right. Anatomical causes of breathing difficulties may also be found, such as a deviated nasal septum, nasal polyps, and enlarged adenoids and tonsils
5- drain the affected sinus to test for organisms ( culture)
In the past, doctors relied on x-ray films for diagnosis because the symptoms of acute sinusitis are very similar to those of an acute upper respiratory tract infection. In fact, most of the time, a viral infection is required to promote sinusitis.
However, these films are not specific and depend on a good technique by the technician.
According to one study, sinusitis is not visible on x-ray films about 55% of the time .
If symptoms continue beyond 7-10 days and are associated with a simple cold, a diagnosis of sinusitis may be possible.
A CT scan may indicate a sinus infection if any of these conditions is present:
1-Air-fluid levels in 1 or more sinuses
2-Total blockage in 1 or more sinuses
3-Thickening of the inner lining (mucosa) of the sinuses
Mucosal thickening can occur in people without symptoms of sinusitis. Therefore, CT scan findings must be correlated with a person's symptoms and physical examination findings to diagnose a sinus infection.
Bear in mind, however, that results depend on the state of the sinusitis (i.e. acute or chronic), patient compliance (i.e. whether cutting down on smoking, attending treatment) and most importantly, early referral achieves quicker results which inevitably saves on medical costs.