Ask the Allergists

With Dr. Susan Waserman and Dr. Wade Watson

Q We’ve been given the opportunity to purchase a lakefront lot at a good price. However, the property has some hazelnut trees, and our three kids are allergic to tree nuts and peanuts. Could being in the presence of these trees cause a reaction (aside from the risk of hazelnuts on the ground)? What do you think?

Dr. Waserman: Allergy to hazelnut is highly associated with tree pollen allergy, especially to birch, hazel and oak. If a person is tree-pollen allergic, inhaling the pollen in season can lead to nasal and eye symptoms.
As you have stated, the main risk for your tree-nut allergic kids is with handling or ingesting the hazelnuts on the ground, if the shells have broken. Just the presence of the trees, or contact with the leaves or branches should not cause an allergic reaction.
If you have this opportunity, reasonable precautions such as avoidance of the actual nuts can make this a safe investment.

Q I have food and seasonal allergies, but I don't get the flu as often as my non-allergic siblings do. So is there an upside to being allergic? Is my immune system more vigilant than the norm?

Dr. Waserman: The best answer I can give is "maybe." In the past, research has suggested that people with allergies might be less likely to develop cancer, and it has been proposed that the higher immune activation in allergic people might be responsible. Researchers have hypothesized that hormone-like proteins called cytokines, which are produced by the immune system during allergic responses, may boost the activity of certain white blood cells called "natural killer" (NK) cells.
NK cells are highly specialized units able to detect the changes in tissues that indicate cancerous mutation or infection. When NK cells detect such alterations, they send signals to the suspect cells that cause them to commit suicide, thereby halting the progression of the cancer or infection. The production of NK-activating cytokines during allergic reactions could theoretically make allergic people more resistant to infection or cancer. At present, however, this remains an unproven theory, so we can't say that there's a definitive upside to being allergic!

Q We’re considering buying a great townhome. However, close behind it is a busy downtown expressway. I have asthma, and I’m worried that air pollution could lead to asthma in our 2-year-old. My husband thinks I’m being over-cautious. Am I?

Dr. Watson: You are not being over-cautious. There is mounting evidence that traffic exposure (living within 100 metres of a road with more than 10 cars per minute) is associated with a higher prevalence of allergic asthma and allergic rhinitis in adults.
A recent study suggested that exposure to traffic exhaust contributed to the development of respiratory symptoms in healthy children. There was conflicting evidence as to whether the exhaust fumes actually “caused” allergies or whether children with a certain genetic makeup were more likely to develop allergies in an environment of heavy traffic. Another study found that children who lived within 500 metres of a freeway since 10 years of age had reduced lung function by the age of 18 when compared to children living at least 1,500 metres away from it.
It’s difficult to give you specific advice. The association with asthma, genes and the environment is complicated. If you have a choice, I would recommend looking for a great townhouse elsewhere.

Q My son is allergic to peanuts, tree nuts and all seeds. I’m curious about the seed allergies: why is sesame viewed as a major allergen and declared in the ingredients of foods while sunflower seeds and oil are not? Also, since seeds are an issue, should we be worrying about mustard and mustard seed?

Dr. Watson: I have reviewed the Canadian Food Inspection Agency website with regard to food labeling. Currently, the 10 priority food allergens identified by the CFIA were declared as they account for more than 90 per cent of severe adverse reactions related to food. They include peanuts, nuts, sesame seed, milk, egg, fish, shellfish, soy, wheat and sulphites. My interpretation would be that sunflower seeds were not part of this group because they were responsible for fewer reactions. For your son, I realize that this is not relevant.
Mustard is, indeed, a seed. There have been a number of reviews of cross-reactivity in food allergy. Although there are a number of seed storage proteins, cross-reaction between seeds is not common. The most important question is “Does your child currently eat mustard?” If the answer is “no”, then there is no issue. If the answer is “yes”, the risk is extraordinarily low. I would suggest you talk to your allergist about any precautions to take if introducing mustard to his diet.

Q I have ragweed allergies, and seem to be getting more congestion and weepy eyes in the late fall – when the ground on the streets around my home is covered with leaves showing black spot and mould. Could the mould be my problem?

Dr. Watson: New allergies can develop any time. Mould allergies occur in the late fall and early spring. In the late fall, there are usually dead and dying vegetation, plus increased dampness. Outdoor moulds peak during this time. There is also a smaller peak in the early spring when the snow starts to melt.
Mould may indeed be a problem. I would talk to your doctor/allergist about this issue. Avoid raking leaves and other fall cleanups, as this may reduce your symptoms. In addition, you may need both antihistamines; and topical and nasal corticosteroids.

Q My food-allergic child is in daycare. The daycare’s advisory committee is grappling with the question: Is it safe to administer the epinephrine auto-injector if a child is unconscious? What would you advise them?

Dr. Waserman: I would advise them that it is safe. If a child is having an anaphylactic reaction, epinephrine is the first line treatment, and there is no exception to this rule. Severe allergic reactions may cause a drop in blood pressure and result in a loss of consciousness. One of the actions of epinephrine is to reverse this effect.   
If there is uncertainty as to whether this is an allergic reaction or whether it’s a panic attack or fainting spell, if there is reason to suspect anaphylaxis (e.g. the child is reacting shortly after eating), then my advice is to treat with the epinephrine and then figure out the cause later. The biggest mistake in treating anaphylaxis is time delay in administering the auto-injector. This condition can be life-threatening and patients are much more likely to respond to epinephrine if it is given early in a reaction.

Q I’m a little embarrassed but here goes: I’m quite allergic to shellfish and recently, my husband ate shrimp at a cocktail function and, as usual, came home and brushed his teeth and washed his hands and face. Later that evening, we had sexual intercourse and afterward I noticed some hives on my torso. It wasn’t anaphylaxis or anything, and Reactine made the hives go away – but could shrimp protein actually be in semen and cause a reaction? My husband thinks I just got worried and that caused the hives.

Dr. Watson: There are really three questions here. First: Is it possible for food allergens to be transmitted via semen? Interestingly there is one recent case report suggesting that it is possible. In that report, the patient was at risk of anaphylaxis to nuts and had an anaphylactic reaction after sexual intercourse with her partner, who had consumed a certain type of nut several hours before. Apparently he had showered, brushed his teeth and cleaned his nails just before intercourse. A skin test conducted with the partner’s semen some time after that reaction was negative – before he again consumed the same kind of nut. But 2.5 hours after eating the nut, a test with semen was positive. I am not suggesting that you and your husband undergo similar testing. I would not consider this a standard test!
The next question is: Although it may be possible, is it likely? It is not clear from your question as to the seriousness of the reaction. It sounds like you had a few hives on your abdomen. Could any of your spouse’s body fluids come in contact with that area? Were there any other signs or symptoms of an allergic reaction? If the answer is “no” to both, it is highly unlikely that this was related to the ingestion of the seafood. If the answer is yes, it may be possible.
The final question: Have you had hives for no other reasons before? A few hives can appear for no obvious reason. At this point, it seems unlikely that this could have been an allergic reaction. As always, if there is doubt, exercise caution.

Q Last year, at age 37, I was diagnosed with oral allergy syndrome. It has been difficult understanding that my allergies to birch and grass are related to newfound allergies to several vegetables and fruits (including celery, carrots, tomatoes, beans, apples and grapes). My symptoms, especially with tomatoes and celery, include severe itchiness and rash around and in my mouth, as well as some tightening of the throat.I’ve heard that some people with this syndrome can be at risk of anaphylaxis, especially to some nuts. How do you know if you’re at that level of risk?

Dr. Waserman: Oral allergy syndrome (OAS) is an allergic reaction to certain proteins found in a variety of fruits, vegetables, and nuts. This develops in some people with birch tree or ragweed pollen allergy. OAS usually affects the mouth, lips and throat, causing symptoms like the ones you are describing. OAS occurs because the allergy-causing IgE antibody, which reacts with pollen protein, also reacts to similar proteins in the food. Cooking usually destroys the food allergens in fruits and vegetables, and those foods can then be eaten safely. Nut proteins are more resistant to cooking, and can still cause symptoms, sometimes severe. I would recommend that fruits and vegetables that have caused symptoms only be eaten cooked. If you are eating nuts without difficulty, continue to do so. Though anaphylaxis from OAS is uncommon, nuts should be avoided if you are experiencing symptoms. See your allergist who may perform skin-prick tests and provide further information on your “level of risk”.

Q My daughter has allergies to egg, tree nuts, peanuts and sesame. We recently purchased a handcrafted wooden salad bowl sealed with walnut oil that’s derived from the walnut husk and shell, not the meat. The oil penetrates the wooden bowl to form a hard seal. Both the craftsman and the walnut oil distributor indicated they had investigated but have never heard of an allergic reaction from anyone using their products. Is it likely a person with nut allergies would have a reaction eating salad from such a bowl?

Dr. Watson: Your question is an interesting one. Most tree nut allergens identified to date are seed storage proteins that are not found in the shell or husk. The fact that the oil penetrates the bowl and forms a hard seal would suggest that there would be very little chance of any proteins leaching from the bowl.
I realize I keep saying this over and over in this column, but I give the same advice to my patients all the time: if you are concerned, don’t use the bowl for your daughter. There are alternatives

Q My 5-year-old daughter has several food allergies (eggs, peanuts, sesame, peas), and recently tested allergic to fish and shellfish. In past, sometimes the only safe thing she could eat at a restaurant was French fries. But now with the fish allergy, I’m wondering: is it OK for the French fries to be fried in the same oil as fish? Some places do serve fish and chips.

Dr. Watson: The question of French fries fried in the same oil as fish is one that I have been asked for many years. In my opinion, it is not safe to eat French fries that are fried in the same oil as fish. Even though the oil is at a very high temperature, I would worry about contamination of the French fries.
I have reviewed the medical literature and cannot find any study to support this opinion, but most allergy information websites recommend avoiding French fries if they have been cooked in the same oil as fish or seafood. Why take a chance?

Q My 31⁄2 year old daughter has a tree nut allergy, confirmed by a skin test at age 2 after a reaction to a cashew. She is to return to the allergist for retesting at 4. If she still tests positive for all tree nuts, is it possible to get a RAST test for each specific tree nut? Is there a minimum age for RAST testing?

Dr. Waserman: The RAST (radioallergosorbent test) is a blood test that measures circulating IgE antibodies to a specific allergen. A positive test means you may be allergic. A negative test does not necessarily mean that you’re not allergic. There is a high false-negative rate.
It is certainly possible to do A RAST for each specific tree nut. There is no minimum age for RAST to ensure maximum sensitivity and specificity. It can be done effectively at any age.

Q My daughter has an extreme allergy to tree nuts, and now there are so many soaps and lotions out there with shea nuts or shea nut butter or oil. I have never heard of this “nut” before. Is it a true nut? If it is, am I right to assume that my daughter should avoid the many products that contain it?

Dr. Watson: Interestingly, the shea fruit is similar in appearance to avocado. The shea tree grows in the Sahel region of West Africa. As an aside, the harvesting and processing of shea is primarily an activity of rural women (300,000 to 400,000 in Burkina Faso alone). The fruity part of the nut, when crushed, yields a vegetable oil that is used, not only in cooking, but also in soap-making and skincare and hair-care products. This is what you have seen in products.
With regard to your question as to whether or not this is a true nut, the Food Allergy Research and Resource Program reports the shea nuts are a tree nut, but that they do not belong in the list of commonly allergenic tree nuts. There are no reports of allergic reactions to shea nuts or its products. For soaps and cosmetics, it is the oil from the shea nut that is used. The oil contains little protein, which is what triggers the allergic reaction. As with everything, if you are worried or doubtful, avoid the product. I am sure there will be further information with regard to this product in the future.

Q My 8-year-old son is at risk of anaphylaxis to tree nuts and soy and wears a pouch with two EpiPens in it. The EpiPen label says they should be stored at 15 to 30 degrees C. What happens if the auto-injector gets too cold or hot? My son likes to be outside and active – I just want to know that when he needs his EpiPen, it will work.

Dr. Waserman: Epinephrine, the medication in the EpiPen, is light sensitive. Usual storage instructions are to keep it at 25 degrees C, but the temperature can vary between 15 to 30 degrees C.
If an EpiPen or Twinject auto-injector is exposed to low or high temperatures, check the colour of the solution. If it is discoloured or cloudy (precipitate), it’s time to replace it. As long as neither problem is present it should be effective when used.

Q I have three children, aged 12, 7 and 18 months. My 12-year-old daughter developed peanut allergy at 2. My 7-year-old daughter had a test at 3 and wasn’t allergic to peanut. Now at age 7, she is.
Why is that? And is there anything preventative I can do for my 18-month-old son?

Dr. Watson: Unfortunately, peanut allergy is increasing. A negative skin or blood test for peanut allergy in a child before they are exposed to peanut only tells you that they have not yet made any IgE, the allergic antibodies, to peanut. It does not predict the development of an allergy. For children who have outgrown their peanut allergy, regularly eating peanut appears to reduce the risk of the peanut allergy coming back. It is not known if this is true for children who do not have a peanut allergy. So it is difficult to know why your second child developed her peanut allergy at age 7. Was she eating peanut regularly?
For your third child, I would exercise caution because of your other children’s allergies. I would keep peanut-containing products out of the house. There are no good studies that say prevention of an allergy is possible, so I cannot make a scientific recommendation. The longer you avoid peanut exposure, the more you may delay a possible allergic reaction. If you decide to have your son tested, I would recommend doing so before school, while he’s under your supervision. If the test is negative, then you will need to decide whether you are comfortable with continuing to avoid peanut versus feeding it to him regularly. I wish I knew the right answer. I do not, but neither does any other allergist. This is an area of heated debate.

Q My two children are active in (ice) ringette, and I usually sit on the bench with the coach. Every year there are a couple of players who are exercise-induced asthmatics. What do we do if one has an asthma attack, and how do you tell if it is one? If they have their puffers, do you just administer another dose? I carry an EpiPen, should I use that if the breathing doesn’t improve?

Dr. Watson: Children with asthma may have symptoms with exercise. Several triggers in indoor rinks include cold air, moulds, plus the exhaust from the Zamboni machine. Symptoms of an asthma attack may include spasms of cough, wheezing and difficulty breathing. The person may complain of chest tightness and use the muscles in the neck and stomach to help them breathe during an attack.
There are several ways to reduce exercise-induced symptoms. If a child with asthma does a vigorous warm up, such as four to six cycles of running on the spot for 30 to 60 seconds with minimal pauses, he or she will frequently get a little bit of tightness of the airways. Once this relaxes, there may be a “refractory period,” or time where the child is able to do further activities without having symptoms. In addition, such children are advised to use a dose of their short-acting bronchodilator (the blue puffer) before their activities. If they develop symptoms after exercise, it’s common to have them rest for a short time and give an extra dose of their bronchodilator.
Your question about the EpiPen is interesting. With children who have had severe life-threatening asthma episodes in the past, we have advised that an EpiPen be carried, but this is not a common recommendation. I would recommend that you discuss emergency procedures with the coach and make sure there are individualized asthma action plans for any children with asthma

Q I am allergic to soy and would like to know: should I be concerned about eating chicken that may have
been fed soy as part of its grain diet?

Dr. Waserman: I am not aware of this being a problem. The soy protein is extensively broken down through the process of digestion, and is no longer allergenic. Similarly, people with shellfish allergy may not experience symptoms when eating fish, even though shellfish may make up part of the fish’s diet

Q I’m highly allergic to cats and wondered if there are allergy shots for cats that are effective. I have heard there is such a treatment, but does it help?

Dr. Watson: Immunotherapy (allergy shots) is used to “turn down” the allergic response to a particular substance. It is not used to replace avoidance of your allergic triggers. Many times it is not effective because people are allergic to a number of triggers for which allergy shots are not used, or the dose of the shot is not high enough to change the allergic response. There is a risk of anaphylaxis with immunotherapy, so this needs to be balanced with the possible benefits.
For cat allergy, avoidance of cats is the primary recommendation. The use of antihistamines for short-term exposure and anti-inflammatory medicines is recommended when avoidance is not possible. There are few studies of allergy shots for cat allergy. Using a standard cat allergy extract, changes in the immune responses can be shown early. Symptom relief is harder to assess, since the only way to measure symptoms is to expose the person to a known amount of cat allergen and measure their symptoms.
There are more recent studies looking at T-cell allergy vaccines for cat (targeting the cell which regulates the allergic response). Changes in the cell responses were seen, but there were delayed asthma and hay fever symptoms. Allergy shots will not yet replace avoidance.

Q The medical community says there is no clear proof that eating peanuts while pregnant will cause peanut allergy in offspring, but doctors still suggest against it for those with a family history of peanut allergy.
What about a family history of other allergies? Do doctors also advise pregnant women who already have dairy-allergic or egg-allergic children to refrain from eating those foods? If not, is there something different about peanut protein that causes the medical community to only warn against peanuts?

Dr. Waserman: You have correctly identified the inconsistency where physicians will recommend peanut avoidance in pregnancy even though there is not good evidence that peanut ingestion during pregnancy will cause peanut allergy. Researchers may shed some light on this in the future, since they are currently examining whether feeding peanut in pregnancy will lead to peanut tolerance in the offspring.
In the meantime, yes, peanut is different than egg and milk. Egg and milk allergy are generally outgrown in about 80 per cent of 5- to 6-year-old children, whereas most peanut allergy is lifelong. Because of this, and because egg and milk are staple foods for pregnant mothers, most physicians do not recommend egg and mik avoidance in pregnancy as a means of preventing allergy.
Peanut is also a more potent allergen. It cannot be destroyed by boiling or other food preparation, and it is still one of the most common causes of fatal anaphylaxis. In the absence of better information, peanut avoidance is still recommended with full disclosure to the patient that physicians do not have all the answers, and cannot guarantee this will, in fact, do anything to prevent peanut allergy.

Q We recently rushed our 7-year-old son, Ethan, to the ER with a nighttime asthma attack (I think caused by his pollen allergies). It was frightening and I feel like such a bad mother – I’d been relying on the Ventolin, not wanting to use the controller medication. (Ethan doesn’t always have symptoms.)
I learned that was wrong and really want to understand his asthma better. We now have him on the orange puffer, with the blue used only as backup. The respirologist (who’s hard to get an appointment with) said to watch out for symptoms that suggest he needs to be adjusted on his controller meds. But now I’m not sure – I still hear Ethan coughing some nights. Do we need to adjust? Any advice is greatly appreciated.

Dr. Watson: The goal for asthma treatment is control. The definition of asthma control is daytime asthma symptoms (cough, wheezing or shortness of breath) fewer than three days per week, no nighttime symptoms, normal physical activity, need for rescue medication (examples Ventolin, Bricanyl) no more than three doses per week, infrequent asthma attacks and no school missed.
It is not clear what type or dose of the controller medication your son is using. It’s also not clear how much coughing he has at night. Cough from asthma typically comes in spasms, and is usually worse between 2 and 6 in the morning. The cough may or may not wake him up at night.
It is important to assess if he is having any symptoms at other times. If he has none and the cough at night is mild, you likely have control of the asthma. If the cough is severe and he also has symptoms with exercise during the day and needs his rescue medication more than three times a week, the asthma is not controlled. Poor control should lead you to reassess his controller medication.
Always remember that cough at night may also be related to other medical conditions such as post-nasal drip related to hay fever. If you are not sure, have him reassessed by your doctor.

Q I was stung by a wasp last year, with no reaction. About three weeks later I was stung again and my lips and ears swelled, as did my arm where I was stung, hives broke out and I got a pounding headache. I’ve been told I’m anaphylactic now, and I’m really afraid when I’m outside. How do I go on living a normal life? Might venom therapy be a possibility?

Dr. Watson: Venom immunotherapy for people who have had anaphylactic reactions can be very helpful. The risk of having an anaphylactic reaction to a wasp’s sting is reduced from approximately 50 per cent to less than 5 per cent.
I would recommend that you see an allergist to find out whether immunotherapy is an option for you. More importantly, you should carry an EpiPen and know how to use it to treat a reaction.
While severe reactions to bees and wasps can be very scary, it is important that you take control with steps to reduce the chance of being stung. Bees and wasps are attracted to odours and bright colours in the environment. Avoid looking or smelling like a flower. Do not use perfume, cologne, or scented soaps and don’t wear brightly coloured or patterned clothing. Avoid going barefoot while outside, especially in clover and blooming ground covers.
If a bee or wasp lands on your skin, remain calm. The insect will eventually leave on its own. If you don’t want to wait for it to fly off, gently and slowly brush it away with a piece of paper. When swimming in pools, watch out for and remove bees or wasps trapped on the surface of the water.
Stinging incidents often occur when nests are disturbed. If you see insects flying to and from a place, avoid it. If you are going to be in an area where disturbing a nest is possible, such as an old building or in the woods, wear long pants and a long-sleeved shirt.

Q I have oral allergy syndrome to apples, strawberries, cherries, carrots and am allergic to nuts. Recently my daughter told me that raw celery made her mouth tingle. Should I have her avoid (or reduce) all raw fruits and vegetables in the same category?

Dr. Watson: Oral allergy syndrome (OAS) is primarily an allergy to pollen. Typically, this relates to an allergy to birch or ragweed pollen, since there are proteins in the pollens that are similar to proteins in a number of fruits and vegetables. The primary problem is not a food allergy, and avoidance of all fruits and vegetables will not make any difference in the progression of oral allergy symptoms.
Some children react to one or two fruits and vegetables, while others will react to many.It is important that you sort out whether your daughter also has pollen allergies to discover if this is, in fact, OAS. Some people can react to fresh fruits and vegetables as a primary food allergy and, if this is the case, your daughter could be at risk for a more severe reaction to these foods. You will need the help of an allergist to sort out this problem.

Q My son has life-threatening allergies to sesame and peanut. Recently, sunflower seeds were added to the list. He has eaten many foods with sunflower oil (dried fruits, potato chips, etc.) over the years with no reaction. Is it possible he's allergic to the seeds but not the oils? Eliminating foods with sunflower oils means he can't have any snack foods with his friends.

Dr. Waserman: People with food allergy react to small proteins in the food. Traditionally it has been thought that since oil is a fat, it contains little or no protein, and therefore cannot cause allergy. But the amount of protein in the oil depends on the method used in processing, with the more refined oils containing lower traces of protein.
Caution is needed as there are medical reports of individuals reacting to both peanut and sunflower oil. There is the potential risk of reaction to oil products of sunflower seed, especially in highly allergic individuals. In your son’s case, he can continue to eat those foods with sunflower oil that he has repeatedly tolerated. I would, though, exercise caution with new foods.

Q I am a marine biologist who loves sushi. Lately when I east fish, raw or cooked my mouth gets very itchy. I have never before had any food allergies, but I do work with large amounts of seafood, preparing diets for marine animals daily. My co-workers suggested that could have caused my new sensitivity. If I continue eating fish, will the allergy develop to a more severe reaction?

Dr. Watson: I am concerned about the reactions that you are having. The symptoms that you are having to both raw and cooked fish do, indeed, sound allergic in nature. Your occupation as a marine biologist may have increased your risk in that you have been exposed to fish through contact with your skin or inhaling molecules of fish into your lungs.
I think it would be very important for you to see an allergist to have this problem reviewed and to get more specific advice. In the meantime, wearing gloves may be helpful. I am uncertain whether there are any facemasks that could protect against inhaled seafood proteins, but I suggest you research this. This is not something to be relaxed about. Life-threatening reactions can occur with fish and shellfish. Ask your doctor about carrying an epinephrine auto-injector to treat serious allergic reactions.

Q My 5-year-old daughter tested positive to peanut on a skin-prick test. Since these tests can have false positive results, should I ask her allergist to do a RAST assay as well?

Dr. Waserman: If your child has already had an adverse reaction to peanut, a positive skin test is generally sufficient to make the diagnosis. If she has never eaten peanut, yet has a positive skin reaction, an oral challenge with peanut may be necessary to test for allergy. A radioallergosorbent test (RAST) can tell whether your child has IgE antibody against peanut in her blood, and may help your physician to decide whether an oral challenge with peanut is appropriate.
In a challenge, the child eats the suspect food under medical supervision and is observed for any allergic reaction. This procedure allows the physician to diagnose conclusively a food allergy that is otherwise not obvious. A RAST is also useful when a skin test is not possible, as in a patient with severe eczema or someone on antihistamines, which interfere with skin tests. A RAST may also help to determine how serious a child's reaction to an allergenic food will be and also if the child has outgrown the allergy.

Q I’m 16 and a competitive soccer player. I’ve had environmental allergies for a long time, then last year my doctor said I now have asthma. Last summer, I had to use my puffer immediately any time our school mowed the grass, and even then sometimes I still started wheezing. I love soccer, and don’t want
to quit – what can I do?

Dr. Watson: It sounds like your allergies have changed. While allergy to grass pollen may be the obvious trigger, allergies to out-of-door mould may also be a problem. Since your symptoms have worsened, it would be very worthwhile to have your allergies reassessed.
The next issue to deal with is whether your asthma is under control. Are there any symptoms at other times? Do you have cough, wheezing, or shortness of breath with indoor activities? Does your asthma wake you up at night? Are you using any controller medications for your asthma? If you are only using a bronchodilator (puffer), it relieves the cough and wheezing, but does not reduce swelling and inflammation in your airways. You may need to use an anti-inflammatory medication for your asthma, such as an inhaled corticosteroid or oral antileukotriene medicine. Speak to your family doctor or allergist.
Finally, if you are allergic to grass pollens and are still having symptoms despite using controller medicines for your asthma, grass pollen immunotherapy (allergy shots) may be helpful. Allergy shots are not meant to replace use of medications, but to reduce symptoms during the grass pollen season. Again, ask your allergist if you would be a good candidate for this treatment.

Q I have an allergy to wheat and avoid obvious wheat-containing products. But what products contain hidden wheat?

Dr. Waserman: Always read ingredient lists on packages carefully. I assume you avoid wheat flour and breads, but watch out for the following: bread crumbs and coating mixes, cakes, cereals (which may be cross-contaminated with wheat), cookies, crackers, donuts, muffins, pasta, baking powder, battered fried foods, processed meat, poultry and fish products (which contain binders and fillers).
Be wary of candy, candy bars, snack foods, canned and thickened soups, coffee substitutes made from cereal, and any products containing gelatinized starch, modified starch, modified food starch, vegetable starch or vegetable gum. Be careful of icing sugar, mustard, seasonings, natural flavouring (from malt, wheat), and commercial condiments (chutney, soy sauce). Be aware that medications, vitamin pills, cosmetics, hair-care products and pet food may also contain starch.

Q I react to crustaceans and scaled fish. But could I try some squid, octopus or cuttlefish?

Dr. Watson: With food allergies, it is important to remember that some proteins are found in many different foods, and these may cross-react with closely related proteins in other foods. For example, the protein tropomycin is found in both shrimp and squid.
Less is known about shared or similar proteins in octopus and shrimp, although there are reports of similar proteins in squid and octopus. Since there is always the potential for reacting to these other types of seafood, I would recommend avoidance. Why take a chance?

Q My eczema gets bad in the winter and I'd like to put a humidifier on my furnace. But my son has asthma and I'm afraid that humidifying will promote the growth of moulds and dust mites. What should I do?

Dr. Waserman: Humidifiers can indeed encourage the growth of moulds and dust mites, both of which can aggravate asthma in people allergic to them. The humidity level of the air should always be kept below 50 per cent. You can get a humidifier that monitors indoor humidity and, like a thermostat, automatically adjusts levels to prevent the formation of condensation and excess moisture.
Be sure to maintain your humidifier by cleaning the evaporating element and drain lines and by using only distilled water. Some units are better for allergies than others: avoid cool-mist humidifiers, as these are associated with greater dispersal of moulds and allergens than the warm-mist (evaporative or steam vapour) variety.

Q My 5-year-old son gets a lot of respiratory tract infections - from strep throat to colds and coughs. Could he have allergies?

Dr. Watson: Allergies do not typically increase the risk of strep throat and colds. The most likely cause of his frequent colds is increased exposure to infected children in the school setting. Sorting out colds from allergies can be difficult. Coughing related to a cold usually lasts from four to seven days and is generally accompanied by a yellow discharge from the nose and perhaps a mild fever. The cough tends to be worse during the day.
Coughing related to allergies is generally associated with asthma or a post-nasal drip from the nose. Symptoms are likely to last longer than two weeks and there is no fever.
A cough triggered by asthma usually comes in spasms and worsens at night and with activity, as opposed to cold-cough which tends to be three or four coughs at a time and occurs throughout the day. If the cough is related to a post-nasal drip from nasal allergies, there is usually a clear nasal discharge and bouts of sneezing typically accompany the cough.

Q My son has severe allergy to tree nuts and peanuts. He is taking a woodworking shop and the teacher questions if he should be working around walnut wood or other woods. He has never reacted from fumes of nuts. (Also, the current shop has a new ventilation system.)

Dr. Waserman: The question of whether the woods of nut trees are a risk for those with nut allergy comes up frequently. In the case of peanut or tree nut allergy, the proteins which are responsible for the allergic reaction are concentrated in the nuts themselves, with only very small amounts elsewhere in the plant. Reactions generally take place after shelling a nut or eating it.
Reactions to various woods have not been reported, so are probably rare. Your son should be able to participate in a woodworking shop safely. The fact that the shop is well-ventilated is wise additional protection, as is having an epinephrine auto-injector on hand.

Q My daughter has asthma and we are visiting Banff this summer. I’d like to visit the hot springs there but I understand they release hydrogen sulphide gas. Should I be concerned about this causing an asthmatic episode?

Dr. Watson: You’re correct. Hydrogen sulphide gas is released from hot springs because the hot water dissolves the minerals in the surrounding rock. It’s responsible for the odour, and this gas can also be found in some workplaces, such as sawmills.
There have been studies to see if there is a relationship between chronic exposure to hydrogen sulphide (and other sulphur gases) and asthma attacks as well as other lung diseases. In one study, there were no changes in airway function in adults with asthma who were exposed to hydrogen sulphide gas for 30 minutes when they were considered as a group, although two individuals had significant changes in airway function.It is difficult to answer your question. If your child’s asthma is well controlled, there may be little risk. I cannot say, though, that there is no risk. If you are concerned, then I would suggest that your daughter avoid the hot springs.

Dr. Susan Waserman is an allergist and Associate Professor in the Division of Allergy and Clinical Immunology at McMaster University in Hamilton, Ont. She is also a past president of the Canadian Society of Allergy and Clinical Immunology.

Dr. Wade Watson is a pediatric allergist and Professor of Pediatrics at Dalhousie University. He is also the head of the Division of Allergy at the IWK Health Centre in Halifax.

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