Food allergy symptoms occur most often in babies and children but can appear at any age. Foods that you have eaten without problems for years can cause allergies.
Types of food allergies
An allergy occurs when something causes your body’s natural defenses to overreact. Some 40-50 million Americans have an allergy of some kind, but food allergies are rare. Up to 4 percent of adults and 8 percent of children have food allergies.
By using caution and carefully following an allergist’s advice, you can bring food allergy under control.
The body’s natural defense network is called the immune system. It keeps you healthy by fighting off infections and other dangers to good health. Most people have no problem eating many kinds of foods. An allergic reaction occurs when the immune system recognizes a specific food or something in a food as harmful by mistake. This battle causes:
Blood vessels to swell up
Smooth muscles to contract
Skin areas to become red, itchy and swollen
Why do I have food allergy?
If you have one child with a peanut allergy, then the risk for a sibling to have a peanut allergy is increased to 7%. If both your parents have allergies, you have about a 75 percent chance of being allergic. If one of your parents is allergic, or if one of your relatives from either side has allergies, you have a 30-40 percent chance of having some form of allergy yourself. If neither parent has allergy, the chance is only 10-15 percent.
Which foods are most likely to cause allergy?
Almost any food can start an allergy. Peanuts, tree nuts and shellfish often cause severe food allergies. In children, the most common food allergies are milk, egg, soy, wheat, peanut, chicken, and fish.
Someone allergic to a food may also react to related foods. A person allergic to walnuts may also react to pecans. Persons allergic to shrimp may also react to crab and lobster. A person allergic to peanuts may have problems with soy, peas or certain kinds of beans.
Most food allergy patients only react to one or two foods.
Food Allergy Symptoms
An allergic reaction to food, can cause any of the following symptoms:
Swelling of the lips, tongue, or face
Difficulty breathing, swallowing, or respiratory collapse
Hives or skin rash
Stuffy nose, sneezing and runny nose
Some mild food allergy symptoms may be caused by a food sensitivity rather than an allergic reaction. An allergist can help determine if it is a true allergic reaction.
Shellfish, peanuts and tree nuts are the most common food allergens for adults. Milk, eggs, soy, wheat, shellfish, peanuts and tree nuts are the most common food allergens for children.
Food Allergy Diagnosis
Diagnosing food allergies can be as complicated as the medical condition itself. Symptoms of food allergy can vary from person to person, and a single individual may not always experience the same symptoms during every reaction. Food allergic reactions can affect the skin, respiratory tract, gastrointestinal tract, and/or cardiovascular system, and people develop food allergies at various ages.
Diagnostic food allergy testing offers clues about the causes of symptoms. When a food allergy is suspected, it is important to consult with an allergist who can determine which food allergy tests to perform, determine if food allergy exists, and counsel patients on food allergy management once the diagnosis has been established.
To make a diagnosis, Dr. Zachary will ask detailed questions about the history of allergy symptoms. Be prepared to answer questions about the specific foods and the quantities you consumed, the length of time that it took for symptoms to develop, the symptoms themselves, and how long they lasted. Dr. Zachary may order a blood test (such as an ImmunoCAP test) and/or perform a skin prick food allergy tests, which indicate whether food-specific IgE antibodies are present in your body.
Skin prick tests are conducted in our office and provide results within 15 minutes – 30 minutes. These tests are administered on the patient’s arm or back by pricking the skin with a sterile small probe that contains a tiny amount of the food allergen. The tests, which are not painful but can be uncomfortable, are considered positive if a wheal (resembling a mosquito bite bump) develops at the site.
The blood tests, which are less sensitive than skin prick tests, measure the amount of IgE antibody to the specific food(s) being tested. Results are typically available in about one to two weeks and are reported as a numerical value.
Dr. Zachary will interpret these results and use them to aid in a diagnosis. While both of these diagnostic tools can signal a food allergy, neither is conclusive. A positive test result to a specific food does not always indicate that a patient will react to that food when it’s eaten. A negative test is more helpful to rule out a food allergy. Neither test, by its level of IgE antibodies or the size of the wheal, necessarily predicts the severity of a food allergic reaction.
In some cases, Dr. Zachary may wish to conduct an oral food challenge. This procedure can be time-consuming, and in some cases is potentially dangerous, so it is not routinely performed.
During an oral food challenge, the patient is fed tiny amounts of the suspected allergy-causing food in increasing doses over a period of time under strict supervision by an allergist. Emergency medication and emergency equipment must be on hand during this procedure. Oral food challenges also may be performed to determine if a patient has outgrown a food allergy.
Once a food allergy is certain, the best treatment is to avoid the food. You need to carefully check ingredient labels of food products. You should learn other names for the food or foods that you and your doctor think it best to avoid to be sure not to eat them.
When you eat out, you should be extra careful. Waiters (and sometimes the kitchen staff) may not always know every dish ingredient on the restaurant’s menu. Sometimes, even walking into a kitchen or an eatery where food is being prepared can cause a dangerous reaction. Vapor may carry extremely small particles that can be harmful.
All patients with food allergies must make some changes in the foods they eat. Dr. Zachary can direct you to helpful resources, such as:
Special food allergy cookbooks
Patient support groups
What if I eat a food I’m allergic to?
You need to have a clear plan of action in case you eat a food you shouldn’t. Place a list of symptoms and your doctor’s instructions for treatment within easy reach in your kitchen. Medications can be very useful in treating many early symptoms of mild food allergies.
If you have had severe allergic reactions, you need to know when and how to give yourself a shot of epinephrine (adrenaline) to treat a severe reaction. You should go to the hospital or call 9-1-1 and arrange for follow-up care when the reaction is severe. Bracelets or necklaces may be worn to quickly alert medical personnel or other caretakers about food allergies.
Will I ever be able to eat these foods again?
Over time, allergies to cow’s milk, eggs and soy may disappear. Allergies to peanuts, tree nuts, fish and shellfish typically last a lifetime. About 20 percent of children who had food allergies at some point are eventually free from food allergies after very carefully avoiding the foods.
After you have avoided foods causing allergies for at least six months, Dr. Zachary may want to run a test, under observation, to see if you are cured. If you have no reaction and can eat a normal portion of the food, you will be able to start eating the food again if you wish. If any allergy symptoms occur, you should continue to avoid the foods.
Once you have had a severe, sudden, life-threatening reaction to a certain food you may be advised to never again eat this food. In some very allergic persons, a very small quantity of a food can produce a life-threatening reaction.
By using caution and carefully following an allergist’s advice, you can bring food allergy under control. Please contact us with further questions and concerns about food allergy.
ADVERSE REACTIONS TO FOOD ADDITIVES
If you had to guess how many additives were commonly used in food today, what would you guess? A dozen? Fifty? Maybe 100 at the most? Would you believe anywhere from 2,000 or more? That’s right-preservatives, conditioners, flavorings, colorants, sweeteners and the like are added to the food we eat every day. What is even more startling, is that out of these thousands, surprisingly few have been reported to cause adverse reactions when ingested, and then only in some susceptible people.
FOOD ADDITIVES THAT MAY CAUSE ADVERSE REACTIONS
Additive Name – Purpose
Aspartame – Sweetener
Benzoates – Preservatives
BHA, BHT – Antidetoxidants
FD&C – Colorants
MSG – Flavoring
Nitrates/Nitrites – Preservatives
Parabens – Preservatives
Sulfites – Preservatives
Here’s a closer look at the additives that cause adverse reactions, the foods and beverages they are commonly found in, and the reactions they have been reported to induce. It should be noted that not all reported reactions have been scientifically verified.
Aspartame – More widely known by its brand name, NutraSweet, this low-calorie sweetener is found in many foods and beverages in place of sugar. Recent studies suggest that aspartame can cause angioedema, or swelling of the eyelids, lips, hands or feet, in those who are sensitive to it. However, the incidence of these symptoms is extremely rare, and research in this area is continuing.
Benzoates – Benzoates are used as a food preservative and in the processing of certain foods, including bananas, cake, cereals, chocolate, dressings, fats, licorice, margarine, mayonnaise, powdered milk, oils, powdered potatoes, and dry yeast. True allergic reactions are extremely rare.
BHA/BHT – BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoulene) are antioxidants, or agents that prevent oxygen absorption. BHA and BHT are used mainly in foods containing fats and oils, primarily in cereal and other grain products. These additives can cause hives and other skin reactions in people who are sensitive to them although true allergic reactions are rare.
FD&C Dyes – The Food, Drug and Cosmetic Act of 1938 gave raise to the term FD&C (food dye & coloring). This Act approved a variety of dyes used in foods and beverages. They are identified on labels by color and number, such as FD&C Yellow NO. 5 (Tartrazine) or FD&C Red No. 3 Some foods that may contain tartrazine include: cake mixes, candies, canned vegetables, cheese, chewing gum, hot dogs, ice cream, orange drinks, salad dressings, seasoning salts, soft drinks, and catsup. Newer studies indicate that FD&C yellow No. 5 very rarely causes hives, urticaria or asthma attacks in those who are sensitive to the agent.
MSG – Monosodium glutamate is best known for its role in Chinese, Japanese and Southeast Asian cooking, which is why MSG reactions are sometimes called the “Chinese Restaurant Syndrome.” However, this association is misleading because MSG is used not only in Oriental foods, but by many different manufactures and restaurants as a flavor enhancer for a variety of foods. Reported reactions to this agent include headaches, nausea, diarrhea, sweating, chest tightness, and a burning sensation along the back of the neck. Such reactions appear to require the consumption of large amounts of MSG. Reportedly, asthmatics who have consumed MSG have more severe asthma attacks, although this remains an area of continuing research, as asthmatic reactions to MSG are extremely rare.
Nitrates/Nitrites – These two agents are widely used as preservatives, though they also serve as flavor enhancers and colorants. Nitrates and nitrites are primarily found in processed meats such as hot dogs, bologna and salami. Nitrates and nitrites may cause headaches and possible hives in some individuals.
Parabens – Parabens are preservatives used in food and drugs. Examples of these agents include methyl, ethyl, propyl, butyl parabens, and sodium benzoate. When ingested by individuals who are sensitive to them, parabens have been shown to cause severe contact dermatitis or redness, swelling, itching, and pain of the skin.
Sulfites – Also called SO2, sulfating agents such as sulfur dioxide, sodium or potassium sulfite, bisulfite, and metabisulfite are used to preserve foods and sanitize containers for fermented beverages. Sulfites can be found in many foods, including baked goods, teas, condiments and relishes, processed seafood products, jams and jellies, dried fruit, fruit juices, canned and dehydrated vegetables, frozen and dehydrated potatoes and soup mixes. They also are found in some beverages, such as beer, wine, wine coolers, and hard cider.
Sulfites may cause reactions such as chest tightness, hives, abdominal cramps, diarrhea, lowered blood pressure, light-headedness, weakness, and an elevated pulse rate. Sulfites also may trigger asthma attacks in sulfite-sensitive asthmatics.
Until recently, the highest levels of sulfites were found in restaurant salad bars. But in 1986, the Food and Drug Administration banned their use on fruits and vegetables intended to be sold or served raw because of the growing rate of sulfite reaction incidences. The FDA, in 1987, also ordered that packaged foods be labeled when they contain more that 10 parts per million of any sulfating agent, so sulfite-sensitive individuals may identify which packaged foods they should avoid.
MANAGING FOOD ADDITIVE SENSITIVITY
The best way to handle food additive sensitivity is to know which foods contain certain additives, and to avoid those additives that cause problems for you. Your allergist can help you identify those food items responsible for your symptoms and eliminate them, as much as possible, from your diet.