Food Allergies
FOOD ALLERGY is an abnormal response by the immune system to food proteins. There are generally two levels of allergic sensitivity to food: a rapid, life-threatening reaction with swelling, hives and airway distress (anaphylaxis) and a group of delayed, more subtle symptoms, such as bloating, diarrhea, even ear and sinus infections (less severe sensitivity). Finally, there are reactions to food which are not caused by the immune system (food intolerance). However, these symptoms can look and feel like those of a food allergy.
1. Anaphylaxis
The prominent symptoms are swelling, especially of the eyelids, face, lips, and tongue (angioedema), rashes – often red skin blotches (hives), and itching of the mouth, throat, eyes and skin. Other dangerous symptoms are wheezing, shortness of breath, or difficulty swallowing.
In adults, the foods that most often trigger severe allergic reactions include:
• Fish and shellfish, such as shrimp, lobster and crab
• Peanuts
• Tree nuts, such as walnuts
• Eggs
It is a misconception that allergies to strawberries and tomatoes are common.
In children, problem foods are milk, eggs and peanuts.
2. Less severe sensitivity
People usually have a sensitivity to the proteins in corn, wheat, milk or soy. The symptoms are often more subdued, such as nausea, vomiting, diarrhea, stomach cramps, or abdominal pain, runny nose or nasal congestion, and mood swings or depression.
3. Food intolerance.
Sometimes a reaction to food is not an allergy. It is often a reaction called "food intolerance". In other words, there is some other explanation than an allergy for the digestive symptoms.
Although 25 percent of people think they're allergic to certain foods, 6-8% of children under the age of six have food allergies and that number is 2-4% for adults. The number of people with food allergies may be rising.
Family history is important. If both parents have allergies, you have a 75% chance of being allergic. If one parent is allergic or if you have relatives with allergies, you have a 30-40% chance of developing a food allergy.
Although children suffer most commonly from food allergies, this condition can appear at any age and can be caused by foods that had been previously eaten without any problem.
- Lactose intolerance- this generally develops later in life. This is due to an enzyme deficiency (lactase) and not allergy. It occurs in many non-Western people. This is an inability to digest milk sugar. The symptoms of gas, bloating, cramping and/or diarrhea occur about 2-3 hours after drinking milk or eating ice cream. An immediate reaction is not a lactose intolerance. And a reaction to cheese is unlikely a lactose intolerance because cheese is low in lactose. A reaction to cheese is more likely a milk or mold allergy. Treatment is the use of Lactaid, the missing enzyme. Unlike some food allergies, this is not life-threatening.
- Celiac disease - this is an autoimmune disorder triggered by specific gluten proteins such as gliadin (present in wheat, rye and barley). More information about celiac disease - printable.
- Irritable bowel syndrome (IBS) - a common problem causing symptoms of bloating, cramping, constipation and /or diarrhea, hours or days after ingestion. Although many IBS cases might be due to food hypersensitivity- not allergic reaction, this is a diagnosis can be identified by an elimination diet.
- C1 esterase deficiency syndrome (hereditary angioedema) - This rare disease generally causes repeated attacks of tongue and lip swelling, but can present solely with abdominal pain and occasional diarrhea.
- Food Additives - While natural foods cause the most allergic reactions, there is recent evidence that a variety of common food dyes, such as yellow No. 5, and some food additives, such as the flavored syrup tartrazine, the artificial sweetener aspartame (brand name: NutraSweet) and the preservative sodium benzoate – an ingredient in many soft drinks, fruit juices and salad dressings – do cause some kids to become measurably more hyperactive and distractible. The additives affect younger children more than older.
Some of the leading foods containing food dyes:
Baked good, candy, cheeses, gum, jam, soft drinks and soup
SYMPTOMS of food allergy
Allergic reactions to food typically begin within minutes to a few hours after eating the offending food. The frequency and severity of symptoms vary widely from one person to another. Mildly allergic persons may only suffer a runny nose with sneezing, while highly allergic persons experience life-threatening reactions, such as swelling of the tongue, lips and throat.
Most common symptoms of food allergy
Skin: rashes, including hives and eczema
Intestine: vomiting, nausea, stomach cramps, indigestion and diarrhea
Asthma: cough and wheezing
Rhinitis: itchy, stuffy, runny nose with sneezing
CROSS REACTIVITY - If you are allergic to a particular food group, you may be allergic to related foods. For example, a person allergic to walnuts may also be allergic to pecans and a person allergic to shrimp may not tolerate crab or lobster. A person allergic to peanuts my not tolerate members of the legume family, such as soy, peas or beans.
Nonetheless, most people with a food allergy are only allergic to 1 or 2 foods. Restriction of all foods in a botanical family based on an allergy to one of its members is rarely necessary.
Children
Milk and soy allergies in children can often go undiagnosed. Many infants with milk and soy allergies can show signs of colic, blood in the stool, mucous in the stool, reflux, rashes and ear infections. These conditions are often misdiagnosed as viruses or colic.
Some children who are allergic to cow's milk protein also show a cross sensitivity to soy-based products. There are infant formulas in which the milk and soy proteins are degraded so when taken by an infant, their immune system does not recognize the allergen and they can safely consume the product. Other formulas, based on free amino acids, are even more safe and provide complete nutrition support in severe forms of milk allergy.
About 50% of children with allergies to milk, egg, soy and wheat will outgrow their allergy by the age of 6. Those that are still allergic by the age of 12 are much less likely to outgrow the allergy.
Peanut and tree nut allergies are less likely to be outgrown, although evidence now shows that about 20% of those with peanut allergies and 9% of those with tree nut allergies will outgrow their allergies.
Milk allergy is much more common in children than in adults. However, by age 6, over 80 percent outgrow the allergy. Symptoms of milk allergy include hives, vomiting and breathing problems after consuming a dairy product
Those adults who experience symptoms similar to milk allergy are more likely to have lactose intolerance.
DIAGNOSIS of food allergy
For severe sensitivities, a person usually has such a strong reaction to the exposure of these foods that no testing is needed to make the diagnosis.
Because of the unique function of digestive tract, the abnormal immunologic (allergic) response to food can be immediate or delayed by days, making the identification of food allergies difficult.
For the less sensitive reactions, there are two methods for diagnosis:
- blood tests (RAST or ELISA): designed to identify immunologic markers in the body that suggest an immunologic activity towards certain foods.
- elimination (or challenge) diet (Printable diet here)
TREATMENT
Presently, there is no specific cure for food allergies. Everyone with a significant food allergy should carry and be trained in the use of an EpiPen. Our office can provide a prescription and training.
For foods which cause anaphylaxis, there is some recent evidence that immunotherapy (introducing very low amounts of the allergen to the body) may be effective in developing tolerance to the food.
For foods which cause less severe allergic reactions, a rotation diet (Printable diet here) may be the best treatment.
Remember that, although food allergies need to taken seriously, try not to panic. Statistically food allergies cause fewer life-threatening reactions than bee stings and almost never result in loss of life.