Ragweed allergy heats up with climate change

If you think your ragweed allergies are getting worse, you may be right. And global warming may be the culprit. That’s not good news for the estimated 36 million Americans who suffer from ragweed allergy, the primary cause of fall allergy symptoms. Ragweed season unofficially begins August 15.  The pollen counts peak around September 19th.  The season will wind down around November 1.

Global climate change is believed to be making ragweed season worse for allergy sufferers. Recent studies suggest that increasing temperatures and carbon dioxide levels are already resulting in longer ragweed seasons and more concentrated pollen counts. There is a wealth of evidence that climate change has had, and will have, further impact on a variety of allergenic plants. Researchers have decisively linked climate change to longer pollen seasons, greater exposure and increased disease burden for late summer weeds such as ragweed.  Other finding is that increased carbon dioxide has resulted in pollen production increases of 61-90 percent in some ragweed varieties.

According to data, one ragweed plant can produce 1 billion pollen grains in an average season. Due to the grains’ light weight, they can travel up to 400 miles with the breeze, leaving virtually no outdoor place ragweed-free in the continental U.S.

The signs and symptoms include: itchy nose, sneezing, nasal congestion, clear runny nose with red, itchy and swollen eyes.

What can be done to prevent or reduce these signs and symptoms? Use a combination of the following steps. First, individuals who suffer from ragweed allergy can also take simple steps to prevent or relieve symptoms:

1. Keep windows closed to keep pollen outside homes and cars. Use the air conditioner, which filters, cools and dries air.
2. Stay indoors when pollen counts are highest, typically between 10 a.m. and 4 p.m.
3. When outside, breath through an N95 mask to filter out pollen before it enters the nose.
4. Change clothing after time spent outdoors and avoid drying laundry outside.
5. Sleep well by taking a shower before bed to wash pollen from your hair and face, preventing it from ending up on your pillow.

Second, medications can reduce symptoms and should be taken routinely, not as needed during the season.  These include nasal steroid sprays, antihistamines and decongestants. Eye drops can soothe itchy red eyes.

Third, allergy “shots”, or immunotherapy, are effective treatment in up to 90 percent of patients with ragweed allergy. The goal of immunotherapy is to raise the patient’s tolerance levels to the offending pollen up as close to normal levels as possible.

Though ragweed allergy affects about 20% of the U.S. population each year, effective treatments are available for almost every patient. Some may need guidance from their doctor or their allergist. Ask questions. Just don’t suffer passively. You can live fully, when you treat actively.

Dr. Neil Kao, Allergist

Allergic Disease and Asthma Center