What is sinusitis?

By Dr. Karen Fong:                                         

Sinusitis is infection or inflammation of the paranasal sinuses (often just referred to as sinuses), which are air-filled spaces that surround the nasal cavity. Most humans have four pair of paranasal sinuses, including the maxillary, ethmoid, frontal, and sphenoid sinuses. Common symptoms of sinusitis include nasal congestion, nasal drainage, facial pressure or fullness, and a decreased sense of smell.  Sinusitis has been divided into the different categories based on the length of time that symptoms are present. Acute sinusitis generally lasts for less than four weeks, while chronic sinusitis is generally present for longer than 12 weeks. Some patients with chronic sinusitis also have nasal polyps, which are overgrowths of nasal tissue caused by inflammation.

The most common reason for developing sinusitis is an unresolved cold or viral upper respiratory tract infection. Allergies are another common cause of developing sinusitis. In both cases, swelling of the nasal lining causes the openings of the sinuses to become blocked, allowing mucus to build up within the sinuses and bacteria to settle in.

It can be difficult to tell the difference between a viral cold, severe allergies, and a sinus infection. However, the process of developing a bacterial sinus infection usually takes at least 5-7 days. The use of antibiotics to treat symptoms within the first few days is not generally recommended, because antibiotics do not treat viruses or allergies. Overuse of antibiotics can lead to the development of antibiotic-resistant bacteria (or “super-bugs”),

Other medical treatments that are aimed at promoting sinus drainage and decreasing inflammation are helpful for viral colds, severe allergies, and sinusitis, and are often recommended early in the course of treatment. Most are available over-the-counter.  The use of oral decongestants (such as Sudafed (pseudoephedrine) or phenylephrine) which are found in many cold medicines, saline irrigations and nasal saline sprays, and mucus-thinning agents, such as Mucinex (guaifenesin), may be helpful in increasing sinus drainage and relieving congestion. Antihistamines, such as Zyrtec (cetirizine), Claritin (loratadine), or Allegra (fexofenadine) may be helpful if allergies are involved. The generic forms of these medications are widely available under different names and may be less expensive, so ask your pharmacist for assistance. Also, patients with heart conditions or high blood pressure should avoid using oral decongestants (such as Sudafed) unless approved by their physician. The nasal lining can become very dried out during a viral cold or sinus infection, so remember to drink plenty of fluids to promote good drainage from the sinuses. Use of a bedside humidifier at night may also be helpful.

If symptoms fail to improve or begin to worsen over the first 5-7 days, a course of oral antibiotics is often prescribed. The choice of antibiotics is based on what is known about the most common types of bacteria that tend to cause sinusitis.  Some patients may require more than one course of antibiotics for their sinusitis to fully resolve.  If patients fail to resolve with antibiotics, or if they develop sinus infections more than four times a year, a consultation with an ENT physician may be helpful.  An ENT physician (otolaryngologist), can sometimes obtain bacterial cultures from the sinuses to help determine whether an infection has been fully treated, or whether a different type of antibiotic is necessary.  An ENT physician can also examine a patient for anatomic issues or the presence of nasal polyps that may cause them to be more prone to developing frequent sinus infections.

When medical therapy fails, a CT scan of the sinuses may be recommended to evaluate for the continued presence of infection or inflammation within the sinuses that is not clearing, or structural issues that may be contributing to illness.