SARS and Allergies

Is it SARS or allergies? Dr. Greene explores…

Allergy season brings with it sneezing, wheezing, coughing, and runny noses – some of the same symptoms found in SARS.

The linings of our noses contain tiny guardians called mast cells, whose purpose is to protect us from harmful particles in the air we breathe, such as the virus that causes SARS. People with allergies have hypersensitive mast cells that also sound the same alert in response to relatively harmless particles such as pollen, dust, or pet dander.

Pollen is used by plants to reproduce. Come springtime, many plants dress themselves with beautiful, vibrant flowers in an effort to attract birds and bees. These curious visitors carry the pollen from flower to flower, and magic happens.

Many less flashy plants use a different strategy to reproduce. Grasses, weeds, and trees often make smaller, lighter, grains of pollen and depend on the wind to scatter them widely. This windborne pollen, not that produced by flowers, is responsible for most hayfever symptoms.

During their mating season, some plants pump out millions and millions of grains of pollen each day. On dry days after the spring rains, the pollen count is at its highest — especially when it is windy. The symptoms of nasal allergies are at their peak.

But if the symptoms of allergies can be similar to the symptoms of SARS, how does one tell the difference?

Allergies typically feature a clear nasal discharge with sneezing. There may be itchy, watery eyes and/or a dry cough. Often parents notice a “rabbit nose” — a child crinkling her nose to relieve the itchy sensation inside. The “allergic salute” — rubbing the nose with the hand, sometimes leaving a horizontal crease on the nose — is another common sign. “Allergic shiners” — dark circles under the eyes — have long been associated with allergies, but are less predictive than the other symptoms. People with allergies may also have wheezing or difficulty breathing. All of these symptoms might also appear in SARS.

Allergy medications might be expected to bring relief to the allergy sufferer, but would be unlikely to make much of a difference in SARS. And nasal allergies do not cause high fever, chills, shaking, muscle aches, vomiting or diarrhea.

The hallmark symptoms of SARS are fever greater than 100.4 F (38.0 C) and cough (usually a dry cough), difficulty breathing, or other respiratory symptoms. Symptoms found in more than half of the first 138 SARS patients included (in the order of how commonly they appeared):

• fever (in 100 percent of the patients)
• chills and shaking (in over 70 percent of the patients)
• muscle aches (in 60 percent of the patients)
• cough
• headache

Less common symptoms included (also in order):

• dizziness
• productive cough (sputum)
• sore throat
• runny nose
• nausea and vomiting
• diarrhea

When the difference between SARS and allergies is not clear based on the history and the symptoms, lab tests and x-rays may be needed to sort out what is happening.

Of course, SARS and allergies may show up in the same person.

Even though allergies aren’t contagious in traditional ways, we should get in the habit of treating all respiratory secretions as potentially infectious. Covering the nose and mouth during coughing or sneezing is more than polite – it is a public health priority. Carefully disposing of tissues and washing the hands is more than neatness – it is preventive medicine. Instant hand sanitizers or soap and water are good for keeping the hands clean. An EPA approved disinfectant can be used to clean surfaces that may have been contaminated by mucus, saliva, or other body fluids.

If you have allergies, this may be a good year to learn about how to get them under control, for peace of mind and body. Then you and your body’s defenses could enjoy the season undistracted by false alarms.

More infomation on SARS:
SARS Update
SARS Hotel
SARS Kids
Stop Respiratory Infections
SARS – School’s Out
Preventing SARS
Disease – Severe Acute Respiratory Syndrome (SARS)
Asthma and SARS
SARS Unmasked
Prepare for the Worst; Hope for the Best