On the Record: Allergy doc answers sniffly, snuffly questions

By Cheryl Rossi-Staff writer

Do seasonal allergies have you itchy, sniffly and puffy? If you can stop sneezing long enough to focus your bleary eyes, you might want to read what one local allergist has to say.

Dr. Amin Kanani, an allergist of five years who has appeared at numerous medical conferences, sees allergy sufferers both at his South Granville practice and through the Division of Allergy and Clinical Immunology at St. Paul's Hospital. He also teaches fledgling allergists at UBC.

He's a knowledgeable man and a fortunate one-he suffers no allergies.

Courier: What are the most common allergens that affect people this time of year?

Dr. Kanani: Tree pollen is one of the major ones. Tree pollen starts in February and goes until early May, and that's here in the Lower Mainland. In May, grass pollen starts, and that will go all the way until early August. The other common allergies are dust mites and animal dander, cats and dogs.

Courier: What are the most effective treatments for seasonal allergies?

Dr. Kanani: Initially, we want to identify that someone does have allergies going on and what they're allergic to. Then we always try to give them tips on how to reduce the exposure to the allergens. Then if the symptoms are mild, we try non-sedating antihistamines. The older generation antihistamines, like Benadryl, Chlor-Tripolon, have a strong sedation side effect so we tell people to try to avoid those and use the newer ones. If those don't work, then there's special nose sprays and eye drops that we use. The nose sprays are prescription nose sprays. These are different than the over-the-counter ones. The over-the-counter nose sprays like Drystan and Otrivin are not good for allergies, because those your nose can become addicted to if you use them for longer than five days and allergy symptoms can last for many weeks. There's also some good antihistamine eye drops that we use. If these don't work and someone is really suffering a lot or they just cannot tolerate these medications, then allergy shots are an option.

Courier: Antihistamine eye drops, are they usually prescription or over the counter?

Dr. Kanani: The over-the-counter ones are short acting. They last for just a few hours so you have to use them frequently. The prescription ones are longer lasting so you only have to use them once or twice a day.

Courier: Do you believe that seasonal allergies are becoming more prevalent and if so, why do you think this is?

Dr. Kanani: There's definitely an increase that we can see with environmental allergies, like pollen allergies, with food allergies over time and with asthma. It's not clear why this is happening. We've noticed this increase more in westernized countries and less so in developing countries. There are a lot of theories out there as to why this is occurring. One of the theories is called the hygiene hypothesis, that because we're more clean, we use antibiotics more frequently. A child growing up here is exposed to less infections than a child in a developing country. Therefore a child here is exposed to less, their immune system has less to do and it kind of drifts towards that allergy side. That's a very simple way of explaining this theory. There's also some theories out there about our dietary changes and that may be playing a role. People who tend to eat more fish that has more of the omega fatty acids, there's a bit of a decrease in the allergies that are observed in them. It's hypothesized that the omega fatty acids play a role but it's not for sure.

Courier: Do antihistamines have any negative effects on the body?

Dr. Kanani: In general they are pretty safe.

Courier: Do you see alternative theories, including acupuncture, herbal supplements and homeopathy, playing an effective role in dealing with allergies?

Dr. Kanani: I know that they're used quite a bit, but there's no proof as to how effective they are and I think we need to have those studies so people are more informed before they choose those therapies. There are a few studies that have looked at some herbal products and, unfortunately, they didn't show a significant improvement with those herbal products when compared to placebo.

Courier: The western medical model of allergy testing that I'm aware of involves exposing punctures in the skin to possible allergens and looking for reactions. Does this remain your key testing method or is there something new?

Dr. Kanani: We still do skin testing. In some cases we do blood tests but, in general, we rely more on the skin testing. It tends to be more reliable.

Courier: What are the longterm solutions for allergy sufferers and how effective are they?

Dr. Kanani: You're born with the genes that predispose you to developing allergies, so that we cannot change. For things where you cannot remove the allergen, particularly like dust and pollen, the closest thing we have to a cure is actually the allergy shots. They really can change the immune system and modulate it so that it's no longer developing a strong allergy.

Courier: What's the time period when people usually have the shots?

Dr. Kanani: The main shots we use are year-round injections so they initially have to come in once a week for about six weeks to build up the dose. And then it's once a month afterwards for about three to five years. And then when they stop the shot, the benefit goes on for many years.

Courier: What's the rate of effectiveness?

Dr. Kanani: It works in about 60 to 80 per cent of people to the point that they require no medications or much less medication to control their symptoms.

Courier: Is there any promising new testing, treatment or prevention on the horizon?

Dr. Kanani: There's a lot of research work being done into treating allergies and to try to prevent allergies, particularly because we are seeing this rise. There's nothing that's going to be coming out immediately. In Europe they are using sublingual allergy therapy, so instead of getting allergy shots, you actually put a drop underneath your tongue so it's easier to take. It works on the premise of the allergy shots and we're hoping to get that here in Canada soon. There's also research work being done into other types of allergy shots where you don't have to come in as frequently for the injections.

published on 04/13/2007