9 Things You Should Know About Allergic Sinusitis

Allergy and sinus infection symptoms can be pretty similar—and equally miserable. Here's what you should know about the treatments so you can feel better.

Allergic sinusitis basics

It all started with a runny nose and itchy eyes after you spent some time outdoors. Days later, your nose is still stuffy and the pressure on your cheeks and forehead is so intense you can’t even look around or move your head without agony. What gives?

It might be allergic sinusitis, essentially an allergy-induced sinus infection.

But it can be difficult to know since the symptoms of allergies and sinusitis share some similar traits.

Still, there are some fundamental differences in what triggers them and how you should treat them. Here’s what you need to know.

What do sinuses do?

Sinuses serve a purpose besides stirring up agony for our heads. These hollow, air-filled cavities are found within the bones behind your cheeks, forehead, nose, and eyes.

The sinuses warm and moisten air, capture particles from the air you breathe, and produce mucus, which traps bacteria and other germs to remove them from the body. At least most of the time.

When you have a cold or allergy attack, your sinuses can become inflamed and trap the mucus instead of draining it as they routinely do. That’s where the trouble starts brewing—bacteria or other germs can multiply if they can’t drain out of the blocked sinuses.

“The nasal congestion can sometimes lead to sinus pressure and headache. It can be part of the whole allergy complex,” says Daniel Sullivan, MD, an otolaryngologist and surgeon specializing in allergies at the Health First Medical Group in Melbourne, Florida.

What causes trouble with sinuses?

All kinds of tiny particles from every source find their way into our noses every time we breathe. Some can stir up trouble by launching inflammation in the lining of the sinuses for one person, while another may not be bothered.

Here are some risk factors or causes of sinus inflammation:

Symptoms of allergies vs. sinus infections

To further illustrate the differences between allergies and sinus infections, it helps to know the classic symptoms of each condition.


People with hay fever allergies can have one or a combination of the following symptoms:

Sinus infection

Anyone who has had a sinus infection knows how awful the pain is in their cheeks and forehead. Unfortunately, the symptoms don’t end there. You might feel one or more of the symptoms most seen in sinusitis.

  • Thick yellow-green mucus
  • Headache
  • Drippy nose
  • Bad tasting postnatal drip
  • Bad breath
  • Cough
  • Congestion
  • Tooth pain
  • Fever
  • Loss of taste or smell

Key differences in symptoms between nasal allergies and allergic sinusitis

There are a few clues that distinguish allergies from sinusitis. The main one is inflammation in the sinuses that can be seen on imaging tests.

“The gold standard for diagnosis of sinusitis is evidence of inflammation in the sinuses on imaging of your head,” says Arthur W. Wu, MD, co-director of the Cedars-Sinai Sinus Center, and associate professor of surgery, Los Angeles, California.

Beyond that, sinusitis doesn’t usually cause an itchy nose, eyes, or throat, like classic allergy symptoms. But if your temperature is trending higher, that’s a sign of sinusitis on the radar.

“Fever is an obvious tip-off, as is sinus symptoms moving lower into the bronchial tree and bronchial symptoms,” says Jason Sigmon, MD, an otolaryngologist with UCHealth Ear, Nose, and Throat Clinic in Steamboat Springs, Colorado.

And while no one really wants to look, don’t assume that yellow-green mucus means that you definitely have a sinus infection.

“We used to think the color of nasal secretions was an indicator (clear versus discolored) of infection but that’s been shown to not be reliable,” says Dr. Sigmon.

Can allergies cause a sinus infection?

Allergic sinusitis is sometimes confused with nonallergic sinusitis because they share a few symptoms, namely nasal-related ones such as a stuffy nose and postnatal drip.

Still, there are some telltale signs one is allergy-related sinusitis, and one is a sinus infection due to other causes.

Nasal allergy symptoms occur due to your immune system’s reaction to certain allergens, such as pollen, dust, mold, or pet dander. People with nasal allergies are more likely to get sinus infections than people who don’t have allergies.

But why? When allergies are poorly managed, nasal inflammation ensues, opening the door for more trouble.

“If it’s a prolonged bout where the symptoms go on for several days, it often can lead to a sinus infection or something else because the inflammation in your sinuses makes it very hospitable for organisms,” says Dr. Sullivan.

Most of the time, sinusitis stems from a virus, like the common cold. Additionally, it could be from bacteria or a fungus.

Anatomical factors such as nasal polyps or a deviated septum increase the risk and irritants such as spicy foods, perfume, smoke, barometric pressure—and yes, seasonal allergies—can trigger sinusitis.

Types of sinusitis

Sinusitis is either acute or chronic.

Acute sinusitis is a temporary inflammation of the sinuses due to bacteria or a virus. Typically, if symptoms resolve in less than 4 to 8 weeks, it’s considered acute sinusitis.

If bacteria are causing your symptoms, you typically don’t improve within ten days of getting sick or you get worse, even if you felt better early on.

When a virus is to blame, you’re generally ill for less than ten days and it doesn’t tend to get worse.

Chronic sinusitis typically results from prolonged inflammation because the nose and sinuses overreact to what they think is an infection. Most of the time, there isn’t an infection.

However, an infection could be partially to blame if sinusitis worsens from time to time. A general rule of thumb is if you have had more than three sinus infections in a year or have symptoms that last longer than 12 weeks, it’s likely chronic sinusitis.

How is sinusitis diagnosed?

An examination of the throat, nose, and sinuses are to look for the classic signs of sinusitis. Doctors are looking for nasal obstruction, nasal drainage, loss of smell, and facial pressure, Dr. Wu says.

“We also look for evidence of swelling, drainage, and inflammation when we look inside your nose.”

A sinus CT scan uses a camera attached to a long and thin flexible tube inserted into the nose. It sounds like a lot, but it is painless. However, you can ask for a light anesthetic nasal spray to make it more bearable.

Mucus cultures can help identify what is causing the infection. Doctors take samples from the nose or directly from the sinuses. If a bacteria is present, doctors prescribe antibiotics for the specific bacteria type.

If a fungus is found in a culture, anti-fungal agents are the treatment, not antibiotics.

If you are diagnosed with an allergic fungal sinus infection (meaning an allergic reaction to fungi), doctors use oral steroids treat it, as these types of infections don’t respond to anti-fungal agents.

Biopsies may be done when certain fungal infections are suspected of spreading to the bones. It also confirms a rare disorder called immotile cilia syndrome, which causes recurrent chronic sinus infection, bronchitis, and pneumonia

close up of businessman using nasal spray while sitting at deskLightFieldStudios/Getty Images

How do I get allergic sinusitis relief?

The best way to prevent allergy-related sinusitis is to stop seasonal allergies in their tracks by avoiding or at least mitigating your exposure. And you should take these steps to reduce or eliminate indoor allergies if things like dust, mold, and pet dander wage war on your nose.

Still, there might be times when allergy symptoms trigger inflammation of the sinuses. So what do you do if you’re dealing with allergies and sinusitis?

The best option for relief is with anti-inflammatory therapy. “This can include saline sinus irrigations and nasal steroid sprays such as Flonase or Rhinocort,” Dr. Sigmon says.

OTC pain relievers fit the bill for pain and fever. However, if bacteria are present, cross-over allergy medicines appropriate for allergy and sinus infections are best. Nasal steroid sprays, sinus or nasal saline rinses, and decongestants, along with antibiotics to kill the bacteria, should do the trick.

Just stay away from antihistamines. Yes, they are the gold standard to relieve allergy symptoms, but they’ll make everything worse when you have a sinus infection.

“One way of thinking about this is visualizing fluid and infection being trapped or filled in your sinuses, and it is trying to get out. You don’t want to dry this up with antihistamines and make it hang around longer,” says Dr. Sigmon.

While you wait for the medicines to kick in and the inflammation to settle, try relaxing in a steamy shower, use a warm compress on your face, or try these other soothing home remedies for relief.

Now that you know about allergic sinusitis, check out what to know about hay fever.


Lisa Marie Conklin
Lisa Marie Conklin is a Baltimore-based writer and writes regularly about health, pets, and home improvement for The Healthy and Reader's Digest. Her work has also been published in HealthiNation, The Family Handyman, Taste of Home, and Realtor.com, among others.