Medically reviewed by Alana Biggers, MD, MPH on February 24, 2020 — Written by Zawn Villines
An allergy occurs when the body’s immune system overreacts to irritants and allergens. A sinus infection, sometimes called sinusitis, is usually bacterial or viral.
The symptoms of allergies and sinus infections can be very similar. Both issues can cause sinus pain and pressure, a runny nose, congestion, and sneezing. Also, allergies can sometimes lead to sinus infections.
It is important to get an accurate diagnosis because the treatments for allergies and sinus infections are different.
In this article, we discuss the differences between these issues and the treatments for each.
A sinus infection, sometimes called sinusitis, happens when the sinuses become infected or inflamed. There are 4 pairs of sinuses in the skull and face, any of which can develop sinusitis.
A doctor will likely diagnose chronic sinusitis when symptoms have persisted for longer than 12 weeks and medical treatment has not worked.
Chronic sinusitis is more common in people with allergies, asthma, a deviated septum, and other conditions that can block the nose or sinuses.
Allergies, meanwhile, are a type of immune system reaction.
In a person with allergies, the immune system aggressively fights a harmless substance, causing pain and inflammation.
When a person breathes in a substance to which they are allergic and their sinuses become inflamed, a doctor may refer to this as hay fever or allergic rhinitis.
Allergies to inhaled substances, such as dust and dander, can cause inflammation and symptoms that resemble those of sinusitis.
In some cases, an allergy can trigger a sinus infection.
When the sinuses swell in reaction to an allergen or irritant, bacteria and other pathogens can become trapped in the nose, potentially causing an infection.
Sinus infections, on the other hand, do not cause allergies. However, if a person has allergies and sinusitis, the infection can make the allergy symptoms worse.
Sinusitis and allergies can cause swelling in the nasal passages, resulting in congestion, or a stuffy nose. Both issues can also cause headaches and a feeling of pressure in the face.
However, some subtle distinctions can help a person figure out whether they are experiencing an allergic reaction or sinusitis.
Allergies may appear without warning or with changes in the seasons. Sinusitis often follows a cold or another viral infection.
A person may be having an allergic reaction if they have:
- symptoms that come and go or appear only at particular times of the year
- symptoms that appear only in certain situations, such as at a pet store
- itchy, watery eyes
- watery, clear, or thin discharge from the nose
- frequent sneezing
A person may have sinusitis if they experience:
- thick mucus that is yellow or green
- symptoms that do not seem related to certain locations or situations
- pain in the gums or above the teeth
- bad breath
- intense pressure in the face
- a reduced ability to smell or taste
- a fever
A doctor can help diagnose sinusitis or different allergies.
A doctor can diagnose an allergy with testing. An allergist, a physician who specializes in allergies, may take a sample of a person’s blood or skin for testing.
They may also ask the person for more information about their medical history.
A doctor can diagnose sinusitis by:
- performing a physical examination
- asking about symptoms
- considering the person’s medical history
- performing a CT scan
- performing an endoscopy
To identify the cause of symptoms, the clinician may ask whether the person has recently had a cold or been exposed to common allergens.
They may also examine the nose, press on the sinuses, or take a sample of nasal discharge to test for bacteria.
There are a variety of treatments for allergies and sinusitis.
The right allergy treatment depends on the allergen and factors specific to the person.
Some options include using:
- nasal steroids to reduce inflammation
- drugs called mast cell stabilizers
- oral steroid medication
- immunotherapy, which involves slowly exposing the person to small amounts of an allergen to reduce the body’s reaction
- avoiding the allergen
- using an epinephrine autoinjector, if the person has severe allergic reactions
Unblocking the sinuses and nasal passages can help relieve symptoms of sinusitis. This allows the sinuses to drain, reducing the risk of further inflammation and infection.
The following treatments can help:
- sinus flushes
- steam inhalation
- saline sprays to keep the nose clean
- over-the-counter steroid sprays to temporarily reduce inflammation
- prescription steroid sprays
- nasal strips to make breathing easier during sleep
If there is a bacterial infection, the doctor may prescribe antibiotics.
In many cases, a person does not need prescription treatment. According to the American Academy of Asthma, Allergy & Immunology, 70% of people with sinusitis recover without prescription medication.
When a person has chronic sinusitis, a doctor may recommend surgery to remove blockages in the sinuses or nose. This is typically a last resort, and a person may still need ongoing medical treatment to prevent the issue from reoccurring.
Certain strategies can reduce the chances of developing allergies or prevent allergy symptoms from worsening over time.
These strategies involve:
- early exposure to common food allergens, including through breast milk
- early exposure to animals
- avoiding exposure to dust mites by cleaning and dusting regularly and using hypoallergenic bedding
- avoiding exposure to cigarette smoke
Some lifestyle strategies and home treatments may help prevent sinusitis, especially when the issue is chronic.
These strategies involve:
- washing the hands regularly and keeping the nose clean to reduce the spread of infection
- using nasal rinses to cleanse the nasal passages
- treating any allergies to reduce inflammation
- avoiding any allergens
Neither sinusitis nor allergic reactions tend to be medical emergencies. However, a person may develop a severe reaction called anaphylaxis, which can be life threatening.
The following can be symptoms of anaphylaxis:
- difficulty breathing
- a rash
- changes in heart rate
- swelling in the throat
Anyone who experiences these should call 911 or otherwise seek emergency medical care.
If sinusitis results from a bacterial infection and the person does not receive treatment, the infection can spread to other areas of the body. It is crucial to seek prompt treatment for a fever, confusion, chills, or other serious symptoms following a bout of sinusitis.
Anyone who has allergies or sinusitis should see a doctor if:
- symptoms do not go away within 1 week
- symptoms get worse
- symptoms do not improve or worsen with prescription medication
- allergy treatments stop working
The pain and pressure of allergies and sinusitis can make it difficult to sleep and concentrate. This can affect a person’s quality of life.
Both conditions are treatable. A doctor, such as an allergist or otolaryngologist, can help diagnose the issue and recommend a course of action.