One of the most common complaints seen in an ENT office is the reported sinus infection. Symptoms include congestion, headache, runny nose and post-nasal drip. Oh, but wait. Those symptoms are also seen with colds and allergies. So, what’s the difference? How can you tell the difference between colds, allergies and sinus infections? The complaints are similar, and many reported sinus infections don’t ultimately make the diagnostic criteria. In order to separate the different diagnoses, we need to define the anatomy and physiology of the sinuses.
The paranasal sinuses, aptly named because they surround the nose, are air-filled cavities within the face. The most likely purpose is to increase the surface area to warm and moisturize the nose. If the sinuses become inflamed, then you have acute sinusitis. At first, the mucous will be clear. There may be congestion but no headaches. If the sinus openings become obstructed, the mucous will become trapped, and the bacteria will proliferate. Then you have a sinus infection. The congestion persists and the headaches may start. The mucous will likely change color to yellow or green, and a fever may develop. That’s when antibiotics become necessary.
So, how do sinus infections start? Something must cause the original nasal congestion that leads to the sinus blockage. Sometimes, cold and flu viruses may be the cause. Colds are more common in the winter months, but they can occur throughout the year. Sometimes, allergies may be the cause. Allergies are more common in the spring, summer and fall months, but they can also occur throughout the year. Colds may cause a fever, even in the absence of a sinus infection, whereas allergies won’t cause a fever without a bacterial infection.
The healthcare provider should make the diagnosis of a sinus infection before prescribing antibiotics. If no bacterial infection is present, the symptoms can be treated with basic cold and allergy medications, such as nasal steroids, antihistamines and/or decongestants. To diagnose a sinus infection, the healthcare provider should document purulent drainage in the nose by visual inspection. Alternately, radiologic evidence of sinus fluid can be shown by sinus x-ray, but this is less accurate in proving an infection exists. Should fever, congestion and headaches persist for more than a week, antibiotic therapy is acceptable for a presumed sinus infection.
What if sinus infections persist or become recurrent? Then chronic sinusitis may develop. In this scenario, the sinuses remain obstructed for so long that polyps or thickened mucosa may fill the sinuses or clog the openings. The congestion and headaches are generally still present. The yellow or green drainage may persist, but the fever typically diminishes unless an acute infection is present on top of a chronic infection. The diagnosis of chronic sinusitis should be made with a CT scan of the sinuses. If nasal steroids, oral steroids, antibiotics, antihistamines and/or decongestants fail to resolve the symptoms, then endoscopic sinus surgery is indicated in order to open the sinuses and remove any polyps.
So, as cold and flu season or allergy season approaches, symptoms of a sinus infection often occur. The important thing is to accurately determine whether a bacterial infection actually exists. That will decide whether antibiotics are necessary, or whether basic cold and allergy medications will suffice.