Sinusitis, commonly referred to as sinus infection, is defined as inflammation of one or more of the paranasal sinuses. This inflammation may be the result of infection by bacteria, viruses, or fungi, or the result of allergic or autoimmune inflammation.
Sinusitis occurs frequently in both children and adults, affecting over 36 million adults and children each year. Sinusitis is arguably one of the most common, yet under-diagnosed, conditions in infants and young children. This is especially evident during the winter months, when pediatricians’ offices are often filled with children with upper respiratory infections complicated by sinusitis.
Nasal sinuses are hollow, air-filled cavities within the cheek bones that are lined with mucous membranes. Each of the four pairs of sinuses is connected to the nose in order to allowing mucus to drain and air to circulate. The primary function of these sinuses is to warm, moisten, and filter the inspired air. Healthy sinuses are sterile, meaning that they are devoid of bacteria, viruses, or other infectious agents.
Sinusitis can be divided into the following categories: acute, in which symptoms last less than four weeks; sub-acute, with symptoms lasting from 4 to 8 weeks; and chronic sinusitis, with symptoms that last eight weeks or longer. Recurrent sinusitis is characterized by three or more episodes of acute sinusitis per year.
Acute sinusitis usually presents with typical symptoms of a common cold. The common cold generally lasts 7-10 days. If symptoms persist beyond 10-14 days, one should suspect acute sinusitis. These symptoms may include:
Symptoms of chronic sinusitis may be the same as acute sinusitis, but tend to be milder and more subtle. They may include:
Infection of the sinuses usually starts with a viral upper respiratory infection, commonly known as the common cold. The cold virus can cause damage to the lining of the sinuses, predisposing the tissues to colonization with bacteria, a virus, or fungal spores. When infected by a pathogen or inflamed by allergies, the sinuses may become blocked with mucus or by swelling of the mucosal lining. In addition, if the small hairs, or cilia, located in the lining of the sinuses are not working properly, the mucus will not be efficiently removed from the sinuses, resulting in mucus accumulation and thickening, with resultant sinusitis.
Although viral upper respiratory infections are the most common cause of acute sinusitis, people with uncontrolled allergies have a higher likelihood of developing sinusitis. Inhalation of airborne allergens can trigger inflammation of the nose and the lining of the sinuses, resulting in swelling and obstruction of the mucus flow patterns. This inflammation also prevents the sinus cavities from clearing out bacteria, and increases the chances of developing secondary bacterial sinusitis.
Patients with chronic sinusitis should be evaluated for structural problems in the nose. Narrow drainage passages, polyps, tumors, or a severe deviated nasal septum may predispose to one developing sinusitis. Surgical intervention is sometimes needed to correct these problems.
Most cases of acute sinusitis can be diagnosed clinically, without the need for laboratory tests or x-rays. However, a simple sinus x-ray can confirm the diagnosis. To make a diagnosis of chronic sinusitis, a physician will often need to take a detailed history and perform a physical examination. The physician will likely need to order imaging studies including a CT scan (which makes multiple precise images of the sinus cavities), or an MRI. A sampling of the nasal secretions or lining can sometimes be helpful in identifying the causative infective agent. Allergy testing may also be indicated when trying to identify an underlying predisposition to recurrent or chronic sinusitis.
As part of a complete examination, it may also be necessary to directly visualize the area where the sinuses and middle ear drain into the nose. This endoscopic examination is a simple and quick office procedure which involves inserting a narrow, flexible fiberoptic scope into the nasal cavity through the nostrils.
The treatment of both acute and chronic sinusitis generally requires a combination of therapies, with the goals of eliminating infection, reducing swelling and inflammation, and promoting drainage. In addition to prescribing an antibiotic when it is suspected that the sinusitis is caused by bacteria, your physician may prescribe a medication to reduce blockage or control allergies. This medicine may be a decongestant, an expectorant (mucus-thinning medicine), or a cortisone nasal spray. A short course of five days or less of a decongestant nose spray can be extremely helpful in keeping the nasal passages open, especially in acute sinusitis. Oral or injectable steroids are sometimes prescribed to reduce the inflammation in the mucosal lining of the sinuses, therefore enhancing drainage.
The treatment of sinusitis can often be augmented by nasal irrigation with a buffered saline (salt water) solution. This is critical step to keeping the sinus passages open and promoting drainage. Breathing in hot, moist air can also help liquefy the sinus contents to promote drainage.
Allergic individuals who are predisposed to recurrent sinusitis, or chronic sinusitis, may require long-term treatment to control and reduce nasal and sinus inflammation. This treatment may include environmental control measures to reduce exposure to allergens, the use of medicine to minimize allergic inflammation, and immunotherapy. Patients with vasomotor or non-allergic rhinitis are also at a higher risk for sinusitis due to chronic airway inflammation. Besides using anti-inflammatory nose sprays, these individuals should avoid environmental irritants such as tobacco smoke and strong odors, which may increase symptoms.
Consultation with an allergist may be helpful in the diagnosis and treatment of recurrent or chronic sinusitis. If there is evidence of nasal or sinus obstruction predisposing to sinusitis, or if infected sinuses do not respond to aggressive medical therapy, an ENT consultation would be warranted and surgical intervention may be necessary.