Can Sinusitis Be Caused by Allergies?

Can Sinusitis Be Caused by Allergies?

The inflammation of the sinuses found in your forehead, cheekbones, and behind your nose is what is known as sinusitis. Sinusitis can be a short-term inflammation resulting from a bacterial infection after an infection like the common cold. However, sinusitis can also be chronic, resulting from structural issues in the nose or allergies.



Sinuses are openings found in the skull, the forehead, and around the eyes and cheeks.  Tiny tunnels connect them to the nose. Nasal sinuses are found in the cheeks, around and at the back of the nose. Their major function is to moisten, warm, and filter the air in the nose. They are also essential in our ability to vocalize some sounds.

Clogged sinuses can be the result of a cold, an untreated allergy, or nasal polyps, and cause facial pain most of the time. A clogged sinus makes a good environment for bacteria to develop, in the same way that algae develop in stagnant water.


Forms of Sinusitis

Sinusitis has two forms:

  • Acute sinusitis - This infection lasts fewer than 4 weeks, and usually results from a viral respiratory infection like the common cold or allergies left untreated. This diagnosis is made when a bacterial infection develops secondarily from the viral infection and there is sinus drainage obstruction. 
  • Chronic sinusitis - This infection lasts for more than 12 weeks. Chronic sinusitis usually results from a respiratory tract infection (which may be viral, bacterial, or fungal), nasal polyps (growths on the nasal tissue), or a deviated septum. Allergies can also cause blockage in the sinuses, and some complications of other medical conditions can also result in nasal blockage. If not properly treated, chronic sinusitis can persist for months or even years. 


Sinusitis Signs and Symptoms

Sinusitis has numerous signs and symptoms.

The signs and symptoms you experience will be determined by how serious the inflammation is and which sinuses are affected. You may experience some or all of these signs and symptoms:

  • Fatigue
  • Thick mucus that is yellow to green in your nose or at the back of your throat
  • Bad breath
  • Inability to smell or taste, or both
  • Fever
  • Pain or pressure in the face
  • A cough or sore throat
  • Toothache
  • Headache
  • Postnasal drip
  • Obstructive sleep apnea (OSA)
  • A feeling of pressure that worsens when you lean forward



If you experience recurring or chronic sinusitis, further tests may be conducted to determine the primary cause of the infection. The procedures that can be used for this are CT scans, facial X-rays, allergy tests, blood tests, and mucus cultures. A nasal endoscopy may also be conducted. This is a method in which a tiny camera attached to a tube is inserted in the nose of the patient to get a clear image of individual’s sinuses and nasal cavity.

These tests are performed to look for conditions that may be causing the chronic sinusitis, like abnormally shaped sinuses or nasal polyps. These tests are not frequently used in diagnosing simple sinusitis, although they are a valuable diagnostic approach for individuals experiencing recurrent or chronic sinusitis. 


Leading Sinusitis Causes

Sinusitis is an inflammation of the sinuses, usually accompanied by inflammation of the nasal tissue. Most cases result from a viral infection, although bacterial and fungal infections may also cause sinusitis. A bacterial infection may also result from a viral infection and worsen the sinusitis. There are other factors that contribute to the development of sinusitis, and they include smoking or secondhand smoke, a crooked nasal structure, an untreated allergy, the excessive use of decongestant nasal sprays, and nasal polyps. Seasonal rhinitis is caused by allergic reactions to seasonal factors. Sinus pathways become clogged, engorged, and inflamed as they try to eliminate the elements that are causing the allergic condition. An example of a seasonal allergen is pollen. Dust mites, molds, and pet dander can lead to all-year allergic symptoms that often cause chronic sinusitis.



Allergy can result in long-term inflammation of the sinus membranes. The inflammation prevents the normal elimination of bacteria from the sinuses, putting one at risk of secondary bacterial sinusitis. If you have allergies, your physician can recommend preventive measures or prescribe drugs to manage the allergies, thus minimizing your chances of getting sinusitis. Although sinusitis and allergies have nearly similar symptoms and signs, below are the types of rhinitis that end up causing sinusitis.

Allergic rhinitis - This develops when your immune system overreacts to certain, non-infectious substances like molds, animal hair, plant pollen, food, insect venom, industrial chemicals, and medicines. In the case of an allergy, antibodies, mostly Immunoglobin E (IgE), attach to histamine-releasing cells (mast cells) in the skin, lungs, and mucous membranes. Several chemicals are produced when IgE bind to mast cells. Histamine, one of the produced chemicals, opens your blood vessels and results in swelling of the membranes and redness of the skin. Congestion and sneezing occur when this happens.

Hay fever - Also known as seasonal allergic rhinitis, this takes place in spring or late summer. The main cause for this is an allergic reaction to ragweed which affects 75% of American citizens suffering from this condition. Individuals allergic to pollen from trees experience symptoms at the beginning of April or end of March. Hypersensitivity to mold spores takes place in October and November due to the falling of leaves.

Perennial allergic rhinitis - This takes place throughout the year and can occur as a result of being allergic to such things as wallpaper molds, pet hair, upholstery, carpets, and houseplants. According to studies, allergic rhinitis can be triggered by air pollution like emissions from vehicles’ engine. Although allergic rhinitis does not result from bacteria, studies have shown that patients of this condition have a large amount of staphylococcus aureus bacteria in the nasal pathways, leading to a conclusion that the condition may result in high levels of bacteria, thus worsening the allergies.

Individuals experiencing frequent allergic rhinitis need to watch their symptoms regularly. Visit an ENT (ear, nose, and throat) specialist for the right treatment of sinusitis, if you have pain in the face or a nasal secretion that is green to yellow.

Non-allergic rhinitis - This is not determined by the availability of IgE nor is it caused by an allergy. Symptoms can be activated by smoke from cigarettes and other air pollutants, alcoholic drinks, strong smells, and colds. Other causes include a deviated septum, nose blockages, infections, and excessive use of certain drugs, such as decongestants.


Connection Between Allergic Rhinitis and Sinusitis

Sinusitis usually develops after rhinitis and rarely without simultaneous rhinitis. Both conditions have similar symptoms like nasal secretion and blockage, and loss of the sense of smell. Tests using a CT scan have found that the sinuses and nose’s mucous membranes are involved in the common cold. Sinusitis is now referred as rhinosinusitis by otolaryngologists.

Both conditions also involve nasal sinus overflow obstruction, with bacterial colonization following, and infection resulting in recurrent, acute or chronic sinusitis. Similarly, long-term inflammation caused by allergies can result in blockage and subsequent sinusitis.

According to research, there is a close link between sinusitis and allergic rhinitis. A study on sinus irregularities found that there was a frequent thickening the sinus mucous in individuals affected by sinusitis from July to December, months with high levels of mold, pollen, and viral infections. It was also found that individuals who had undergone surgery for the treatment of chronic sinusitis, or had nasal polyps or seasonal allergies, had high chances of getting recurrent sinusitis.

Rhinitis should not be mistaken for sinusitis although they have the same symptoms. Rhinitis is not an inflammation of the paranasal sinuses, but of the nose’s mucus membranes. It often results from allergies, high reaction to irritants like temperature alterations, smoke, or excessive use of decongestants like nasal sprays. Not properly controlling rhinitis can cause sinusitis.