— Lorelei, British Columbia Unfortunately, no — there are no medications that would allow you to eat seafood to which you are allergic. However, if you really enjoy seafood, you could see an allergist to determine whether there are other forms of seafood that you could eat without a reaction. This may involve eating the food in question, but an allergist should first help you weigh the risk of doing this. The three foods you mentioned (clams, mussels, and oysters) are all bivalve mollusks, but there are also sea creatures like squid, the crustaceans (shrimp, lobster, crab), and all the finned fish, and you may not be allergic to any of those. There are two main types of seafood allergies. The more common type is caused by allergic antibodies (IgE antibodies) to proteins in seafood, which activate a person’s allergy cells if that protein is eaten and absorbed. Symptoms include hives, itching, flushing, nausea and vomiting, lightheadedness, throat tightness, wheezing or repeated cough, and perhaps diarrhea or even loss of consciousness. Most people will have just one or two of those symptoms, which generally begin within minutes to an hour after ingestion. This type of allergy is unpredictable and has the potential to be life threatening. The severity of one reaction does not predict the severity of the next, so people who have had this kind of reaction should absolutely avoid the foods that trigger it, carry an epinephrine auto-injector, and see an allergist if they haven’t already. Skin testing or blood tests for IgE that are specific for that food are often positive and can be used to clarify the diagnosis. The other type of allergy seen with some regularity is a reaction that results in crampy abdominal pain, nausea, and vomiting, usually two to four hours after the seafood is eaten. Hives, itching, flushing, and airway constriction are not seen in this kind of reaction, and also you can not check for it by doing skin or blood tests. In both kinds of allergy, there is no known cure or preventive treatment. My best advice is to avoid the foods you react to. You should also know that there are conditions that can mimic seafood allergy, like scombroid poisoning, in which certain fish, when spoiled, contain a lot of histamine and cause symptoms like IgE reactions; another possibility is general food poisoning from seafood. However, if you have had several similar reactions, then you probably have a true allergy. Q2. I’ve heard that vegetable oil may contain additives harmful to people with allergies to soy. Which oil would be better, corn or canola? — Janie, Georgia I recommend canola, but not for the reasons you might think. Let me explain: Most oils consist almost entirely of fat and contain no significant protein. This is important because protein is the component of food to which people become allergic. For this reason, people who are allergic to, say, peanuts can tolerate peanut oil. In your case, your allergy to soy products probably doesn’t extend to soybean oil. However, some oils, especially those described as “extruded,” “cold pressed,” or “expelled,” can contain trace amounts of protein and so may pose a small risk. Because of this, many people with a specific allergy find it simpler to choose a different everyday oil, such as corn or canola. Of the two, research indicates that canola contains more omega-3 fatty acids, which are believed to be helpful in preventing heart disease, so that’s why I recommend it. By the way, olive oil is also rich in omega-3s — and tastes great too. Q3. I believe I am having a reaction from eating pumpkin seeds. Is there something I can take to counteract the all-over itching? There is no rash, just constant itching. Pumpkin seeds are the only thing I changed in my diet. I tried Benadryl (diphenhydramine), but it had no effect. If you suspect pumpkin seeds are leading to an adverse reaction such as itching, stop eating them (if you haven’t already) and see what happens to your itching. There is no prophylactic treatment for food allergy other than avoidance. If your itching persists, I suggest that you seek an allergy evaluation, which would include skin tests for pumpkin seeds and other common airborne and food allergens. If you are not allergic, and your itching hasn’t subsided, then you’ll need additional testing to evaluate your itching. Q4. Two years ago I was having stomach issues and saw a doctor who ran blood tests. The test showed that I was allergic to wheat, but the doctor didn’t suggest it was serious or that I should avoid wheat entirely. I have noticed that when I eat whole wheat bread my throat becomes very itchy and my stomach hurts, but I feel fine eating pasta and white bread. Should I get a more definitive answer about what types of wheat I can or cannot eat or is it safe to simply avoid what I know will bother me? — A., New York It should be safe to keep eating those foods (pasta and white bread) that don’t cause symptoms. However, I would also recommend trying to sort out what is going on with whole wheat, because your symptoms of itching in the throat and stomach aches are suggestive of an allergy. Do you get symptoms every time you eat something with whole wheat, or just once in a while? If the symptoms do not appear every time, then there may be another factor involved. For example, some people will react to a food only if they eat it and then exercise within a few hours; others may react only if they have also taken aspirin, ibuprofen, or other similar anti-inflammatory medicines. It is also possible that the whole wheat bread that causes symptoms actually contains some other component that is the culprit, rather than the wheat itself. Whole wheat breads can contain nuts and seeds, both of which are common allergens. If you can identify a specific whole wheat food that consistently causes symptoms, then an allergist could grind up the food and use it for skin testing. If your skin test to the ground-up bread were positive, then at least you could narrow your allergy down to one of the components in that bread, and then test the ingredients individually. Q5. I have had urticaria for seven years and have had all types of allergy tests. All have come back negative. I have been tested for wheat and found that I’m not allergic. I was wondering if gluten would be covered in that test because I have noticed that after eating bread I get hives. Wheat and gluten are functionally the same for the purposes of evaluating people with hives. Gluten is a component of wheat. Gluten is singled out at times because it is the part of wheat that is problematic for people with celiac disease. These people develop bowel inflammation whenever they eat wheat or other grains containing gluten (e.g., rye or barley). Celiac disease, however, is not known to be related to chronic hives. As I’m sure you are aware, a food allergy does not seem to be a contributing factor for the vast majority of people who suffer from chronic hives. Furthermore, allergy skin tests are very accurate at determining when an allergy is NOT present. A negative skin test is over 97 percent accurate. Q6. My 5-year-old son is showing some signs of a mild food allergy – funny feeling in his mouth, blotchy skin. If I think I know what’s causing it, can I just cut that food out of his diet, or do I need to take him for testing? Both! It definitely makes sense to cut out a food that potentially induces allergies in your child. However, evaluation by an allergist, via skin or blood testing, would also be worthwhile. There are similarities between various foods, and there may be cross-reactions that allergy testing could uncover. Your allergist can then offer specific guidelines for the treatment of your child so that unnecessary reactions don’t occur. Q7. Soy or anything made from soy causes me to cough, have trouble breathing, asthma flare-up, etc. I have tested this theory (my asthma/allergy doctor understands) and know it is a real problem as everything seems to have soy in it. I have nonallergic rhinitis so nothing registers on my scratch tests (have tried twice). Although my breathing/asthma problem doesn’t show up on my peak flow meter, I am still helped when adding the albuterol at these times. I am also on two daily morning puffs of Pulmicort (budesonide). This certainly helps almost all the time unless I ingest soy unknowingly. Any advice except to stay far away from soy? Thanks so much! Soy is ubiquitous and found in many products even in trace amounts – and for someone who’s allergic to soy, even trace amounts can trigger symptoms. You must also be careful about cross contamination – for example, when food is cooked on the same surface as soy or handled with the same utensils – because this puts you at risk of having an adverse reaction. For now, as you’ve already figured out, avoidance of soy is wise behavior. You should also carry diphenhydramine (Benadryl) and even possibly auto-injectable adrenaline such as an EpiPen for cases of accidental exposure. Q8. I’ve recently been diagnosed with shellfish allergy after eating shrimp. Does this increase my risk for being allergic to other types of fish? What do I need to know about cross-contamination and hidden ingredients? You may be at increased risk of other shellfish allergies in the future (clams, lobster, etc.), but not necessarily other seafood allergies (in other words, seafood without shells). It’s also possible that shrimp is your only trigger. For now you should be tested to see if other shellfish need to be avoided. Obviously, you know to avoid shrimp but you should also be wary of cross-contamination. For example, if a utensil that touched shrimp then touches any of the food you will be eating, this may cause you to have an allergic reaction, even if you didn’t eat the shrimp itself. If that happens, you may need to take an antihistamine or even use auto injectable adrenaline to block a life-threatening allergic reaction. For milder reactions, you can try allergy medications to control symptoms but the best approach is to eliminate the food from your diet entirely. Q9. Which types of fruits or vegetables will help decrease inflammation due to allergies? I’ve heard that eating broccoli, tomatoes, avocados, and cherries helps. — Fran, Texas I don’t think that eating more of these particular foods will reduce the inflammation of allergies to a meaningful degree. The dietary intervention that has shown the most promise in scientific studies is a diet rich in the type of fats in fish oils, but you have to be careful with fish oil capsules because they can be contaminated with heavy metals. I have never read or seen a study that claimed that allergies can be treated to any significant degree simply by eating certain foods. I wish it were that easy. Also, fresh fruits and vegetables, although unquestionably good for your overall health, can actually be difficult for some allergic people to eat. For example, people with hives often notice that their hives get worse if they eat a lot of tomatoes, and people with tree pollen allergies often get itching in their mouths when they eat fresh cherries (this is caused by proteins in the cherries that are similar to pollen proteins). Everyone, whether they have allergies or not, should eat a diet rich in fresh fruits and vegetables for all the health benefits those foods can provide. I’m sure there are compounds in certain fruits and vegetables that, when purified and concentrated and poured onto cells in an experiment, may have anti-inflammatory properties. But this does not necessarily mean that eating that food will treat an established allergic problem. I’m afraid you will be disappointed if try to treat your allergies with diet alone. Learn more in the Everyday Health Allergy Center.
