Question: What are seasonal allergies (also known as allergic rhinitis or hay fever)?
Answer: Seasonal allergies is a term used to describe a set of respiratory symptoms that are experienced by people who are allergic to pollen from a variety of trees, grasses, and weeds. A synonymous term that’s been used over the decade has been hay fever, and that’s somewhat of a misnomer because people are actually allergic to the pollen from the living trees, grasses, and weeds, and not so much cut hay. The respiratory symptoms can affect the eyes, the nose, and in a subgroup of people, even their lungs if they have asthma.
Question: What are typical seasonal allergy symptoms?
Answer: Typical seasonal allergy symptoms include runny nose, nasal congestion, post nasal drip, itchy nose, itchy eyes, watering, tearing of the eyes, and in some cases in those that have asthma, you can get the typical asthma symptoms which include shortness of breath, wheezing, cough. Those are the primary symptoms. Now people can additionally experience other types of systemic complaints such as fatigue, they don’t sleep well, and on occasion they may not be able to think clearly or they may have headaches, but these tend to be in the patients that have very severe allergies versus the primary symptoms that I mentioned.
Question: What can cause seasonal allergies at different times of the year? (Early spring, late spring/early summer, fall?)
Answer: Clearly people can have allergies at various times of the year or throughout the year. What causes the symptoms during different times of the year depends on the months of the year. In early spring, the trees are classic pollinators. They begin to pollinate when the weather warms, and they go in to usually April or May depending on where you’re at in the country. After the trees pollinate then the grasses begin to pollinate and they generally peak in June.
And then most allergy patients will have a respite in July and then in mid-August the weeds begin to pollinate heavily and they go on until the first frost. The caveat to this is depending on where you’re at in the country and the local climate, the length of the pollen season and the pollen that’s prevalent varies somewhat depending on the region.
Question: What is the relationship between asthma and allergy?
Answer: People with allergies are definitely more susceptible to asthma. Allergies are immune system reactions to substances -- for instance, dust mites or cat dander -- that lead to the release of chemicals in the blood that cause the symptoms that we associate with allergies, such as an itchy, runny nose at one extreme, but at the other, anaphylactic shock, and even death.
So there’s lots of evidence that people who have allergies are more likely to develop asthma. And that’s usually the sequence of events with early signs of allergy than asthma. However, there are people with asthma who don’t have any allergies, and it’s an important subset that we need to remember.
Rohit Katial, M.D., Dir., Weinberg Clinical Research Unit, National Jewish Medical and Research Center
August 27, 2008