Are Allergies Causing Your Sinus Infection?

Woman with sinusitis caused by allergies
Woman with sinusitis caused by allergies. Maica/Getty Images

What is Sinusitis?

The sinuses are hollow recesses in your skull lined with mucous membranes. The mucous inside of the sinus cavities usually drains into the nasal passageways and subsequently out of the nose or into the back of the throat. Allergies can change this natural process and lead to sinusitis.

There are 2 types of sinusitis (sinus infections):

  • Acute sinusitis usually lasts for 4 weeks or less. Acute sinusitis can be caused by the common cold or by allergies.
  • Chronic sinusitis lasts 3 months or longer. People can often be misdiagnosed with allergies when they actually have chronic sinusitis. Many people suffer from both allergies AND chronic sinusitis and allergies can lead to chronic sinusitis. 

How Allergies Cause Sinusitis

If you have allergies, your body is reacting to allergens in the environment. When the allergen comes into contact with immune cells (mast cells) in your nose and sinuses, histamine is released. Histamine causes inflammation and congestion in your nose and sinuses.

When the mucous membranes in the sinuses become inflamed they swell, making it difficult for them to drain. Excess mucous or mucous that is too thick may also contribute to the problem and the sinuses may become clogged causing pressure and pain. The inability of the sinuses to drain and the lack of airflow create an environment which is ideal for bacterial growth.

Once bacteria start to grow, your allergies have caused sinusitis.

Untreated allergies, over a period of time, can also lead to growths such as nasal polyps inside of the nasal passageways or sinuses. These abnormal growths further inhibit proper ventilation and airflow to the sinus cavities.

Once you develop a sinus infection, allergy medications will no longer be effective to treat the symptoms.

Treatment of chronic sinusitis should involve antibiotic medications and in some cases sinus surgery.

Preventing Sinusitis When You Have Allergies

Adequate treatment of allergies is important in preventing the development of sinusitis. There are 3 keys to preventing the progression of allergies to sinusitis:

  1. monitoring of symptoms by an otolaryngologist and/or allergist (immunologist)
  2. avoiding allergy triggers
  3. nasal irrigation
  4. managing congestion

Mild cases of congestion may be controlled using over-the-counter antihistamines. There are many different medications available including an Allegra, which claims not to cause drowsiness. Claritin (loratadine) and Zyrtec (cetirizine hydrochloride) are also much less sedating than older antihistamines such as Benadryl (diphenhydramine).

Over-the-counter decongestants such as pseudoephedrine or the nasal spray Afrin (oxymetazoline) may also be helpful in managing congestion. However, these decongestants can cause rebound congestion, or nasal spray addiction if used longer than 3 days. Some prescription decongestants claim not to cause rebound congestion or to at least have a lower risk and can be used longer than 3 days.

In most cases, excess mucus caused by allergies is thin, however, if you have thick mucous you should increase your fluid intake, (drink more water!).

Keeping secretions thin will help keep the sinuses draining. A cool mist humidifier or medications like guaifenesin can also be helpful.

A doctor called an allergist or immunologist can test you for allergies, pinpointing the allergic trigger. This is extremely helpful. An allergist can prescribe appropriate medications for allergies and administer immunotherapy (allergy shots) to those who qualify and choose this type of treatment. Allergy symptoms that do not quickly resolve, or do not respond to over-the-counter medications need to be evaluated by a qualified physician.

Complications of Chronic Sinusitis

As briefly mentioned above, untreated chronic sinusitis can damage the tissue inside of the sinuses.

Abnormal growths such as nasal polyps occur frequently in patients with frequent and/or chronic sinus infections. This can result in a cycle of recurrent sinus problems as damaged and enlarged tissues make it even more difficult for the sinuses to drain properly. Of course, some people may be genetically predisposed to these problems as well.

Enlarged turbinates (concha bullosa), deviated septums, and nasal polyps need to be surgically repaired by an otolaryngologist (ear, nose, throat or ENT doctor). Sinus surgery is performed using an endoscope, a long tube with a camera on the end of it which allows the surgeon to see inside of the sinuses. Sinus surgery can usually be performed in a same day surgery setting and you can go home the same day. Once the sinuses have been cleared of diseased tissue and they are able to drain properly, any infection often resolves on its own. In some cases, your surgeon may prescribe you antibiotics after surgery to clear up any remaining infection.


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