Sinusitis is an inflammation of the paranasal sinuses, which may be due to infection, allergy, or autoimmune issues. Most cases are due to a viral infection and resolve over the course of 10 days. It is a common condition with more than 24 million cases occurring in the United States annually.
Inflammation of the sinuses may arise as a result of allergies, upper respiratory tract infections with viruses, bacteria or fungi (yeast infection) although another not commonly recognized cause of inflammation of the sinuses arises from reflux of acid from the stomach (laryngopharyngeal reflux or LPR).
Sinusitis can be classified as acute (going on less than four weeks), subacute (4–8 weeks) or chronic (going on for 8 weeks or more.) All three types of sinusitis have similar symptoms, and are thus often difficult to distinguish. Acute sinusitis is very common. Roughly ninety percent of adults have had sinusitis at some point in their life.
Acute sinusitis is usually precipitated by an earlier upper respiratory tract infection, generally of viral origin. If the infection is of bacterial origin, the most common three causative agents are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Viral sinusitis typically lasts for 7 to 10 days,whereas bacterial sinusitis is more persistent. Approximately 0.5% to 2% of viral sinusitis results in subsequent bacterial sinusitis. It is thought that nasal irritation from nose blowing leads to the secondary bacterial infection.
Acute episodes of sinusitis can also result from fungal invasion. These infections are typically seen in patients with chronic allergies, diabetes or other immune deficiencies (such as AIDS or transplant patients on immunosuppressive anti-rejection medications) and can be life threatening.
Chemical irritation can also trigger sinusitis, commonly from cigarette smoke and chlorine fumes.Rarely, it may be caused by a tooth infection.
Chronic sinusitis, by definition, lasts longer than three months and can be caused by many different diseases that share chronic inflammation of the sinuses as a common symptom. Symptoms of chronic sinusitis may include any combination of the following: nasal congestion, facial pain, headache, night-time coughing, an increase in previously minor or controlled asthma symptoms, general malaise, thick green or yellow discharge, feeling of facial ‘fullness’ or ‘tightness’ that may worsen when bending over, dizziness, aching teeth, and/or halitosis (bad breath). Each of these symptoms has multiple other possible causes, which should be considered and investigated as well. Unless complications occur, fever is not a feature of chronic sinusitis. Often chronic sinusitis can lead to anosmia, a reduced sense of smell. In a small number of cases, acute or chronic maxillary sinusitis is associated with a dental infection. Vertigo, lightheadedness, and blurred vision are not typical in chronic sinusitis and other causes should be investigated.
Chronic sinusitis cases are subdivided into cases with polyps and cases without polyps. The causes for the appearance of polyps are poorly understoodbut may include allergy, environmental factors such as dust or pollution, bacterial infection, or fungus (either allergic, infective, or reactive). Non-allergic factors, such as vasomotor rhinitis (chronic runny nose which is not allergic but may be related to temperature changes), can also cause chronic sinus problems. Abnormally narrow sinus passages, such as having a deviated septum, can impede drainage from the sinus cavities and be a contributing factor. Typically antibiotic treatment provides only a temporary reduction in inflammation, although hyperresponsiveness of the immune system to bacteria has been proposed as a possible cause of sinusitis with polyps.
A more recent, and still debated, development in chronic sinusitis is the role that fungus plays in this disease. Fungus can be found in the nasal cavities and sinuses of most patients with sinusitis, but can also be found in healthy people as well. It remains unclear if fungus is a definite factor in the development of chronic sinusitis and if it is, what the difference may be between those who develop the disease and those who remain symptom free. Trials of antifungal treatments have had mixed results.
The sinuses are paired hollow structures within the skull and the facial bones. They are normally filled with air and are lined with similar mucosal lining as the rest of the respiratory tract is lined with; this means that the sinuses secrete mucous. The sinuses are located behind the cheek bones (also called the maxillary sinuses), behind the prominence of the forehead (frontal sinuses), within the nose on the inside part of the eye sockets (ethmoid sinuses) and deep in the base of the skull behind the nose (called te sphenoid sinus).
Sinusitis can be classified by the sinus cavity which it affects:
- Maxillary – can cause pain or pressure in the maxillary (cheek) area (e.g., toothache, headache)
- Frontal – can cause pain or pressure in the frontal sinus cavity (located above eyes), headache
- Ethmoid – can cause pain or pressure pain between/behind the eyes and headaches
- Sphenoid – can cause pain or pressure behind the eyes, but often refers to the vertex, or top of the head
Recent theories of sinusitis indicate that it often occurs as part of a spectrum of diseases that affect the respiratory tract and is often linked to asthma. All forms of sinusitis may either result in, or be a part of, a generalized inflammation of the airway, so other airway symptoms, such as cough, may be associated with it.
Signs and symptoms
Headache, facial pain or pressure of a dull, constant, or aching sort over the affected sinuses is common with both acute and chronic stages of sinusitis. This pain is typically localized to the involved sinus and may worsen when the affected person bends over or when lying down. Pain often starts on one side of the head and progresses to both sides. Acute and chronic sinusitis may be accompanied by thick nasal discharge that is usually thick yellow or green in colour and may contain pus (purulent) and/or blood. Often a localized headache or toothache is present (especially the upper teeth and more commonly the canine teeth) and it is these symptoms that distinguish a sinus-related headache from other types of headaches, such as tension and migraine headaches. Infection of the eye socket is possible, which may result in the loss of sight and is accompanied by fever and severe illness. Another possible complication is the infection of the bones (osteomyelitis) of the forehead and other facial bones – a condition also known as Pott’s puffy tumor.
Sinus infections can also cause inner ear problems due to the congestion of the nasal passages. This can be demonstrated by dizziness, “a pressurized or heavy head”, or vibrating sensations in the head.
Recent studies suggest that up to 90% of “sinus headaches” are actually migraines.The confusion occurs in part because migraine involves activation of the trigeminal nerves, which innervate both the sinus region and the meninges surrounding the brain. As a result, it is difficult to accurately determine the site from which the pain originates. Additionally, nasal congestion can be a common result of migraine headaches, due to the autonomic nerve stimulation that can also cause in tearing (lacrimation) and a runny nose (rhinorrhea). A study found that patients with “sinus headaches” responded to triptan migraine medications, but stated dissatisfaction with their treatment when they are treated with decongestants or antibiotics.
The close proximity of the brain to the sinuses makes the most dangerous complication of sinusitis, particularly involving the frontal and sphenoid sinuses, infection of the brain by the invasion of anaerobic bacteria through the bones or blood vessels. Abscesses, meningitis, and other life-threatening conditions may result. In extreme cases the patient may experience mild personality changes, headache, altered consciousness, visual problems, and, finally, seizures, coma, and possibly death.
Factors which may predispose someone to developing sinusitis include: allergies; structural abnormalities, such as a deviated septum, small sinus ostia or a concha bullosa; nasal polyps; carrying the cystic fibrosis gene, though research is still tentative; and prior bouts of sinusitis, because each instance may result in increased inflammation of the nasal or sinus mucosa and potentially further narrow the nasal passageways.
Second hand smoke may also be associated with chronic rhinosinusitis.
Another cause of chronic sinusitis can be from the maxillary sinuses that are situated within the cheekbones. Infections and inflammation are more common here than in any of the other paranasal sinuses. This is because the drainage of mucous secretions from the maxillary sinus to the nasal cavity is not very efficient.
Maxillary sinusitis may also be of dental originand constitutes a significant percentage, given the intimacy of the relationship between the teeth and the sinus floor. Complementary tests based on conventional radiology techniques and modern are needed. Their indication is based on the clinical context.
Chronic sinusitis can also be caused indirectly through a common but slight abnormality within the auditory or Eustachian tube, which is connected to the sinus cavities and the throat. This tube is usually almost level with the eye sockets but when this sometimes hereditary abnormality is present, it is below this level and sometimes level with vestibule or nasal entrance. This almost always causes some sort of blockage within the sinus cavities ending in infection and usually resulting in chronic sinusitis.
Bacterial and viral acute sinusitis are difficult to distinguish. However, if symptoms last less than 10 days, it is generally considered viral sinusitis. When symptoms last more than 10 days, it is considered bacterial sinusitis (usually 30% to 50% are bacterial sinusitis). Hospital acquired acute sinusitis can be confirmed by performing a CT scan of the sinuses.
For sinusitis lasting more than eight weeks, diagnostic criteria are lacking. A CT scan is recommended, but this alone is insufficient to confirm the diagnosis. Nasal endoscopy, a CT scan, and clinical symptoms are all used to make a positive diagnosis.A tissue sample for histology and cultures can also be collected and tested. Allergic fungal sinusitis (AFS) is often seen in people with asthma and nasal polyps. Examining multiple biopsy samples can be helpful to confirm the diagnosis.In rare cases, sinusoscopy may be made.
Nasal endoscopy involves inserting a flexible fiber-optic tube with a light and camera at its tip into the nose to examine the nasal passages and sinuses. This is generally a completely painless (although uncomfortable) procedure which takes between five to ten minutes to complete.
Nasal irrigation may help with symptoms of chronic sinusitis. Decongestant nasal sprays containing oxymetazoline may provide relief, but these medications should not be used for more than the recommended period. Longer use may cause rebound sinusitis.Other recommendations include applying a warm, moist washcloth several times a day; drinking sufficient fluids in order to thin the mucus and inhaling steam two to four times a day.
The vast majority of cases of sinusitis are caused by viruses and will therefore resolve without antibiotics.However, if symptoms do not resolve within 10 days, amoxicillin is a reasonable antibiotic to use first for treatment with amoxicillin/clavulanate (Augmentin) being indicated when the patient’s symptoms do not improve on amoxicillin alone. A short-course (3–7 days) of antibiotics seems to be effective for patients who present without severe disease or any complicating factors.
Nasal steroid sprays like flonase, nasonex, rhinocort and others may be prescribed to reduce inflammation within the nasal cavity and sinuses. Sometimes oral steroid medication (like prednisone or medrol dosepak) may be given in order to hasten the resolution of a sinus infection and help to reduce the pain involved.
For chronic or recurring sinusitis, referral to an otolaryngologist specialist may be indicated, and treatment options may include nasal surgery. Surgery should only be considered for those patients who do not experience sufficient relief from optimal medical treatment.
A relatively recent advance in the treatment of sinusitis is a type of surgery called functional endoscopic sinus surgery (FESS). This surgery removes anatomical and pathological obstructions associated with sinusitis in order to restore normal clearance of the sinuses. The benefit of the Functional Endoscopic Sinus Surgery FESS is its ability to allow for a more targeted approach to the affected sinuses, reducing tissue disruption, and minimizing post-operative complications.
Another recently developed treatment is balloon sinuplasty. This method, similar to balloon angioplasty used to “unclog” arteries of the heart, utilizes balloons in an attempt to expand the openings of the sinuses in a less invasive manner. The utility of this treatment for sinus disease is still under debate but appears promising.
For persistent symptoms and disease in patients who have failed medical and the functional endoscopic approaches, older techniques can be used to address the inflammation of the maxillary sinus, such as the Caldwell-Luc radical antrostomy. This surgery involves an incision in the upper gum, opening in the anterior wall of the upper jaw bon, removal of the entire diseased maxillary sinus mucosa and drainage is allowed into the nose by creating a large window in the lateral nasal wall.