Sinusitis vs. Allergies: How to Tell the Difference

Within your skull, just behind your eyes and nose, are four open spaces called sinuses. These help reduce the weight of your skull and also help with circulating and purifying the air that you breathe.

Unfortunately, these spaces can become infected by pathogens such as viruses and bacteria. 

The immune system fights the infection, leading to sinusitis — an inflammation of the sinus tissues. This produces an array of symptoms, including nasal congestion, facial pain, and pressure behind the eyes.

For people with seasonal allergies, their immune systems also fight whatever is triggering the attack. In this case, the reaction is against a harmless substance, such as pollen, pet dander, or dust mites. These also produce symptoms, some of which overlap those of sinusitis. 

So, how can you tell which condition you have?

At Mercy Medical Urgent Care, Dr. Bilal Khoder and our expert staff frequently treat cases of sinusitis and allergies at our Lake City, Florida, office. Because not everyone knows how to tell the difference between the two conditions, we’ve prepared this guide to put you in the know.

Sinusitis 101

Whether caused by a virus, bacterium, or fungus, infected sinus tissue produces several symptoms, including:

• Postnasal drip
• Runny/stuffy nose with thick yellow or green mucus
• Facial pressure that worsens with movement
• Pressure or pain in your teeth, ears, or head
• Fever
• Cough
• Fatigue

The condition isn’t contagious, but the virus, bacterium, or fungus that’s causing the infection may well be.

Sinusitis is classified by the duration of symptoms and the pathogen causing it. It comes in four types:

1. Acute sinusitis: symptoms last less than four weeks and are usually caused by viruses
2. Subacute sinusitis: symptoms last 4-12 weeks
3. Chronic sinusitis: symptoms last 12 weeks or more and are usually caused by bacteria
4. Recurrent acute sinusitis: symptoms recur four or more times a year for less than two weeks each time

Viruses, like those responsible for the common cold, account for most sinusitis cases, but bacteria may also be the cause. 

If your symptoms don’t resolve after 10 days, or if they improve but return worse than before, it’s most likely bacterial. This can be treated with antibiotics.

Allergies 101

As we’ve mentioned, allergies occur when the immune system mistakenly attacks a substance like pollen. The cascade of histamine and other chemicals produces symptoms that include:

• Runny/stuffy nose
• Watery, itchy, red eyes
• Sneezing
• Cough
• Itchy nose, roof of mouth, or throat
• Postnasal drip (mucus drips down the back of your throat)
• Swollen or bruised-appearing skin under the eyes (allergic shiners)

Symptoms last as long as you’re in contact with the allergen and for a short time afterward.

Notably absent from the symptom list are the pain and pressure behind the eyes and nose, facial pain, and fever. This is one way you can tell which of the conditions you have.

Another is the time of year. Since sinusitis is often caused by rhinoviruses that lead to the common cold, it develops more commonly in the winter months, while allergies tend to occur whenever the allergen is present. 

If you’re allergic to pollen, for example, it’s more common to develop symptoms in the spring through early fall when plants are flowering.

If you’ve developed symptoms and aren’t sure what you have, come into Mercy Medical Urgent Care to be tested and find symptom relief. We’re open seven days a week. Walk in, or give us a call at 386-758-2944 to schedule.