Is Your Cold Really an Allergy? Is Your Cold Really an Allergy?
American Academy of Allergy, Asthma and Immunology

What is the difference between allergies and a cold?
What causes the common cold?
What causes allergies and how are they treated?
How can allergies lead to sinusitis?
When should you see an allergist/immunologist?

People often attribute their congestion and runny nose to a cold, but they may not realize that they’re actually suffering from allergies. Left untreated, allergies can cause more serious conditions like sinusitis, an inflammation of one or more of the nasal sinuses, or ear infections. Therefore, it is important to know the difference between a common cold and allergies in order to receive proper treatment for your symptoms.

What is the difference between allergies and a cold?
Cold and allergy symptoms are usually very similar, but the main difference is the length of time that symptoms last. A cold normally disappears after a week. Allergies, on the other hand, can last for weeks or even longer. The following chart provides a few guidelines to help you differentiate between a common cold and allergies.

Allergies vs. Colds

Allergies
Colds

Symptoms
Runny or stuffed nose, sneezing, wheezing, watery and itchy eyes.
Can include fever, body aches and pains, along with allergy symptoms.

Warning Time
Symptoms begin almost immediately after exposure to an allergen.
Symptoms usually develop over several days.

Duration
Symptoms last as long as you are exposed to an allergen and beyond. If the allergen is present year-round, symptoms may be chronic.
Symptoms should clear up within several days to a week.

What causes the common cold?

A cold is caused by a virus. Antibiotics have no effect on viruses, so most people must simply wait for the common cold to run its course. Common symptoms include a sore and scratchy throat, sneezing and a runny nose. Other symptoms may include a high temperature, headache, watery eyes, cough and an achy feeling throughout the entire body. A cold can last anywhere from a week to ten days. During that time, a sick person can easily infect others. For this reason, be sure to frequently wash your hands, use a disinfectant on any contaminated surfaces and be careful when sneezing and coughing around others. Spreading germs is the most common way to catch a cold.

What causes allergies and how are they treated?

Allergies are caused by exposure to airborne allergens, such as dust mites, furry pets, mold, fungi and pollen. Symptoms of allergic disease are the result of events occurring in your immune system, the body’s defense mechanism against harmful substances. The body of an individual with allergic disease identifies certain allergens as harmful. These allergens, which are harmless to most people, trigger allergic reactions within that person’s immune system. Allergies are not contagious, but the symptoms only vary slightly from the common cold, which is contagious. Allergy symptoms include sneezing, watery eyes, coughing, itchiness in the nose and throat, post nasal drip and perhaps a dull headache. Allergy symptoms may last longer than a week, or could even be year-round depending on exposure to the allergen. For example, allergens such as dust mites, animal dander from pets, mold or fungi may produce year-round allergy symptoms. Pollen, on the other hand, causes symptoms of seasonal allergies in the spring and fall.

It is not yet fully understood why some substances trigger allergies and others do not, nor why every person does not develop an allergic reaction after exposure to allergens. A family history of allergies is the single most important factor that predisposes a person to develop allergic disease. If one parent has allergic disease, the estimated risk of the child to develop allergies is 48%; the child’s risk grows to 70% if both parents have allergies.

Although there is no cure for allergies, several treatment options are available, including over-the-counter and prescription medications. Immunotherapy, commonly known as allergy shots, is another alternative. However, immunotherapy is only recommended for allergic asthma, allergic rhinitis, conjunctivitis and stinging insect allergy.

If you have been diagnosed with asthma or allergies, you should see an allergist/immunologist for care. Allergist/immunologists are physicians specially trained to manage and treat allergies and asthma. They are trained in the prevention, diagnosis, and treatment of immune system problems such as allergies, asthma, inherited immunodeficiency diseases, autoimmune diseases and even AIDS. Unlike a cold, allergic disease is not a condition that someone can just “get over.” However, the help of a trained allergist/immunologist can reduce how often patients need to stay home from work or school due to symptoms. Studies show that those under the care of an allergist/immunologist also make fewer visits to emergency rooms, and are better able to daily manage their allergies and asthma.

How can allergies lead to sinusitis?
Millions of Americans think they’re suffering from a cold, when they’re actually experiencing sinusitis.
Sinusitis is an inflammation of one ore more of the nasal sinuses, the hollow cavities within the cheek bones, found around the eyes and behind the nose. Symptoms of sinusitis include:

Nasal congestion
Green or gray nasal discharge
Postnasal drip
Pressure in the face
Headache
Chronic cough
Colds are the most common cause of acute sinusitis, but people with allergies are far more likely to develop sinusitis than those who do not have allergies. Left untreated, allergies can lead to sinusitis. Approximately 31 million Americans develop sinusitis each year, resulting in more than 18 million physician visits and more than $5.8 billion in overall health expenditures.

Allergies can trigger inflammation of the sinuses and nasal mucous linings. This inflammation prevents the sinus cavities from clearing out bacteria, and increases your chances of developing secondary bacterial sinusitis. If you test positive for allergies, your allergist/immunologist can prescribe appropriate medications to control your symptoms, thereby reducing the risk of developing an infection. People with sinus problems and allergies should avoid environmental irritants such as tobacco smoke and strong chemical odors, which may increase symptoms.

If sinusitis is caused by a bacterial infection, treatment begins with an antibiotic. Medications such as decongestants, mucus-thinning medicine or cortisone nasal sprays are prescribed to reduce blockage and control allergies, which should help prevent sinusitis from developing. Antihistamines, cromolyn and topical steroid nasal sprays also help control allergic inflammation and keep the sinus passages open.

When should you see an allergist/immunologist?
The AAAAI’s How the Allergist/Immunologist Can Help: Consultation and Referral Guidelines Citing the Evidence provide information to assist patients and health care professionals in determining when a patient may need consultation or ongoing specialty care from an allergist/immunologist. Patients should see an allergist/immunologist if they:

Need to confirm the diagnosis of allergies or asthma
Need education and guidance in techniques for self-management of allergies or asthma
Are considering immunotherapy (allergy shots)
Have nasal polyps
Have co-existing conditions such as asthma or recurrent sinusitis
Have found medications to be ineffective
Have symptoms interfering with quality of life and/or ability to function
Consulting with an allergist/immunologist before your symptoms begin, or before they worsen, is an important first step in maintaining proper allergy and asthma control. An allergist/immunologist is the best qualified medical professional trained to manage the prevention, diagnosis and treatment of allergic disease. To find an allergist/immunologist in your area, please visit www.aaaai.org/physref.