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ASSIGNMENT ON FOOD ALLERGY

SUBMITTED BY: SUBMITTED TO:

Mr ABHISHEK SINGH Mr A.N SAHU

B.PHARM, PART-3RD PHARM. BIOTECHNOLGY

ROLL NO. 11121EN001

DEPARTMENT OF PHARMACEUTICS

IIT (BHU), VARANASI

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TOPIC PAGE NO Introduction

3

Causes

4-6

Symptoms

7

When to see a doctor?

8-9

Food ingredients and food allergy

10

Common Food allergy

11

Risk factors

12-13

Complications

14

Food allergy or Food Intolerance

14-15

Tests & Diagnosis

16

Treatment & drugs

17

Lifestyle & home remedies

18

Alternative medicine

19

Prevention

20

Special program and resource at the Institute

21-22

Summary

23

Reference 23

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INTRODUCTION

Either food allergy or food intolerance affects nearly everyone at some point. When people have an

unpleasant reaction to something they ate, they often think that they have an allergy to the food. Actually,

however, only about 3% of adults and 6%-8% of children have clinically proven true allergic reactions to

food.

This difference between the prevalence of clinically proven food allergy and the public's perception of the

problem is due primarily to misinterpreting food intolerance or other adverse reactions to food as food

allergy. A true food allergy is an abnormal response to food that is triggered by a specific reaction in the

immune system and expressed by certain, often characteristic, symptoms. Other kinds of reactions to foods

that are not food allergies include food intolerances (such as lactose or milk intolerance), food poisoning,

and toxic reactions. Food intolerance also is an abnormal response to food, and its symptoms can resemble

those of food allergy. Food intolerance, however, is far more prevalent, occurs in a variety of diseases,

and is triggered by several different mechanisms that are distinct from the immunological reaction

responsible for food allergy.

People who have food allergies must identify and prevent them because, although usually mild and not

severe, these reactions can cause devastating illness and, in rare instances, can be fatal. A food allergy is

any adverse reaction to an otherwise harmless food or food component that involves the body’s immune

system. To avoid confusion with other types of adverse reactions to foods, it is important to use the term

“food allergy” or “food hypersensitivity” only when the immune system is involved in causing the

reaction. There are several different types of adverse reactions involving the immune system, which helps

the body resist disease. In the case of food allergy, “immediate hypersensitivity” is the most clearly

understood. This reaction involves three primary components: food allergens, immunoglobulin E (IgE),

and mast cells and basophils. A food allergen is the part of a food that stimulates the immune system of

food-allergic individuals. A single food can contain multiple food allergens, the majority of which are

likely to be proteins, not carbohydrates or fats. People with food allergies produce increased amounts of

IgE, which is an antibody in the immune system. When allergic individuals eat certain foods, their immune

systems are stimulated by the food allergens to make IgE specific to that food. Millions of IgE antibodies

then circulate in the blood; they bind to blood cells called basophils and enter body tissues where they

bind to mast cells. Basophils and mast cells are specialized cells of the immune system that play key roles

in producing allergic reactions. Basophils are phagocytic white blood cells, or cells that engulf and absorb

foreign bodies in the bloodstream. Mast cells are found in tissues primarily at sites in the body that come

in contact with the environment – such as the skin, lungs and gastrointestinal tract. Basophils and mast

cells produce and store various substances such as histamine, which cause allergic symptoms. When IgE

antibodies on the surfaces of basophils and mast cells come in contact with food allergens, these cells

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stimulate the release of mediators such as histamine, prostaglandins and leukotriene’s, which are powerful

compounds that cause allergic reactions.

Relationships between the various types of food sensitivities

CAUSES

Food allergy is an immune system reaction that occurs soon after eating a certain food. Even a tiny amount

of the allergy-causing food can trigger signs and symptoms such as digestive problems, hives or swollen

airways. In some people, a food allergy can cause severe symptoms or even a life-threatening reaction

known as anaphylaxis. Food allergy affects an estimated 6 to 8 percent of children under age 3 and up to

3 percent of adults. While there's no cure, some children outgrow their food allergy as they get older. It's

easy to confuse a food allergy with a much more common reaction known as food intolerance. While

bothersome, food intolerance is a less serious condition that does not involve the immune system. The

allergens in food are those components that are responsible for inciting an allergic reaction. They are

proteins that usually resist the heat of cooking, the acid in the stomach, and the intestinal digestive

enzymes. As a result, the allergens survive to cross the gastrointestinal lining, enter the bloodstream, and

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go to target organs, causing allergic reactions throughout the body. The mechanism of food allergy

involves the immune system and heredity.

Immune system: An allergic reaction to food involves two components of the immune system. One

component is a type of protein, an allergy antibody called immunoglobulin E (IgE), which circulates

through the blood. The other is the mast cell, a specialized cell that stores up histamine and is found in all

tissues of the body. The mast cell is particularly found in areas of the body that are typically involved in

allergic reactions, including the nose and throat, lungs, skin, and gastrointestinal tract.

Heredity: The tendency of an individual to produce IgE against something seemingly as innocuous as

food appears to be inherited. Generally, people with allergies come from families in which allergies are

common -- not necessarily to food but perhaps allergies to pollen, fur, feathers, or drugs. Thus, a person

with two allergic parents is more likely to develop food allergies than someone with one allergic parent.

Mechanism: Food allergy is a hypersensitivity reaction, meaning that before an allergic reaction to an

allergen in food can occur, a person needs to have been exposed previously, or "sensitized," to the food.

At the initial exposure, the allergen stimulates lymphocytes (specialized white blood cells) to produce the

IgE antibody that is specific for the allergen. This IgE then is released and attaches to the surface of the

mast cells in different tissues of the body. The next time the person eats that particular food, its allergen

hones in on the specific IgE antibody on the surface of the mast cells and prompts the cells to release

chemicals such as histamine. Depending upon the tissue in which they are released, these chemicals cause

the various symptoms of food allergy.

When you have a food allergy, your immune system mistakenly identifies a specific food or a substance

in food as something harmful. Your immune system triggers cells to release antibodies known as

immunoglobulin E (IgE) antibodies to neutralize the culprit food or food substance (the allergen). The

next time you eat even the smallest amount of that food, the IgE antibodies sense it and signal your

immune system to release a chemical called histamine, as well as other chemicals, into your bloodstream.

These chemicals cause a range of allergy signs and symptoms. They are responsible for causing allergic

responses that include dripping nose, itchy eyes, dry throat, rashes and hives, nausea, diarrhoea, laboured

breathing, and even anaphylactic shock.

The majority of food allergies are triggered by certain proteins in:

Shellfish, such as shrimp, lobster and crab

Peanuts

Tree nuts, such as walnuts and pecans

Fish

Eggs

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In children, food allergies are commonly triggered by proteins in:

Eggs

Milk

Peanuts

Tree nuts

Wheat

Food intolerance and other reactions

There are a number of reactions to food that cause similar symptoms to a food allergy. Depending on the

type of food intolerance you have, you may be able to eat small amounts of problem foods without a

reaction. By contrast, if you have a true food allergy, even a tiny amount of food may trigger an allergic

reaction. Because a food intolerance may involve some of the same signs and symptoms as a food allergy

does — such as nausea, vomiting, cramping and diarrhoea — people may confuse the two. One of the

tricky aspects of diagnosing food intolerance is that some people are sensitive not to the food itself but to

a substance or ingredient used in the preparation of the food. Common conditions that can cause symptoms

mistaken for a food allergy include:

Absence of an enzyme needed to fully digest a food. You may not have adequate amounts of some

enzymes needed to digest certain foods. Insufficient quantities of the enzyme lactase, for example, reduce

your ability to digest lactose, the main sugar in milk products. Lactose intolerance can cause bloating,

cramping, diarrhoea and excess gas.

Food poisoning. Sometimes food poisoning can mimic an allergic reaction. Bacteria in spoiled tuna and

other fish also can make a toxin that triggers harmful reactions.

Sensitivity to food additives. Some people have digestive reactions and other symptoms after eating

certain food additives. For example, sulphites used to preserve dried fruit, canned goods and wine can

trigger asthma attacks in sensitive people. Other food additives that could trigger severe reactions include

monosodium glutamate (MSG), artificial sweeteners and food colourings.

Histamine toxicity. Certain fish, such as tuna or mackerel, that are not refrigerated properly and that

contain high amounts of bacteria may contain high levels of histamine that trigger symptoms similar to

those of food allergy. Rather than an allergic reaction, this is known as histamine toxicity or comorbid

poisoning.

Celiac disease. While celiac disease is sometimes referred to as a gluten allergy, it isn't a true food allergy.

Like a food allergy, it does involve an immune system response, but it's a unique immune system reaction

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that's more complex than a simple food allergy. This chronic digestive condition is triggered by eating

gluten, a protein found in bread, pasta, cookies, and many other foods containing wheat, barley or rye.

If you have celiac disease and eat foods containing gluten, an immune reaction occurs that causes damage

to the surface of your small intestine, leading to an inability to absorb certain nutrients.

SYMPTOMS

For some people, an allergic reaction to a particular food may be uncomfortable but not severe. For other

people, an allergic food reaction can be frightening and even life threatening. Food allergy symptoms

usually develop within a few minutes to two hours after eating the offending food. The most common

food allergy signs and symptoms include:

Tingling or itching in the mouth

Hives, itching or eczema

Swelling of the lips, face, tongue and throat or other parts of the body

Wheezing, nasal congestion or trouble breathing

Abdominal pain, diarrhoea, nausea or vomiting

Dizziness, light-headedness or fainting

Anaphylaxis

In some people, a food allergy can trigger a severe allergic reaction called anaphylaxis. This can cause

life-threatening signs and symptoms, including:

Constriction and tightening of airways

A swollen throat or the sensation of a lump in your throat that makes it difficult to breathe

Shock with a severe drop in blood pressure

Rapid pulse

Dizziness, light-headedness or loss of consciousness

Emergency treatment is critical for anaphylaxis. Untreated, anaphylaxis can cause a coma or even

death.

Exercise-induced food allergy

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Some people have an allergic reaction to a food triggered by exercise. Eating certain foods may cause you

to feel itchy and lightheaded soon after you start exercising. In serious cases, an exercise-induced food

allergy can cause certain reactions such as hives or anaphylaxis. Not eating for a couple of hours before

exercising and avoiding certain foods may help prevent this problem.

Pollen-food allergy syndrome

In many people who have hay fever, fresh fruits and vegetables and certain nuts and spices can trigger an

allergic reaction that causes the mouth to tingle or itch. In some people, pollen-food allergy syndrome —

sometimes called oral allergy syndrome — can cause swelling of the throat or even anaphylaxis. This is

an example of cross-reactivity. Proteins in fruits and vegetables cause the reaction because they're similar

to those allergy-causing proteins found in certain pollens. For example, if you're allergic to ragweed, you

may also react to melons; if you're allergic to birch pollen, you may also react to apples. Cooking fruits

and vegetables can help you avoid this reaction. Most cooked fruits and vegetables generally don't cause

cross-reactive oral allergy symptoms. Common cross-reactivity between pollens and fruits and vegetables:

When to see a doctor?

See a doctor or allergist if you have food allergy symptoms shortly after eating. If possible, see your doctor

when the allergic reaction is occurring. This will help your doctor make a diagnosis. Seek emergency

treatment if you develop any signs or symptoms of anaphylaxis, such as:

Constriction of airways that makes it difficult to breathe

Shock with a severe drop in blood pressure

Rapid pulse

Dizziness or light-headedness

PREPARING YOUR APPOINTMENT

Because doctor's appointments can be brief, and because there's often a lot of ground to cover, it's a good

idea to be well prepared for your appointment. Here's some information to help you get ready for your

appointment and what to expect from your doctor.

Write down any symptoms you've had, including any that may seem unrelated to the reason for

which you scheduled the appointment.

Write down key personal information, including any major stresses or recent life changes.

Make a list of all medications, vitamins and supplements that you're taking.

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Take a family member or friend along, if possible. Sometimes it can be difficult to remember

all the information provided to you during an appointment. Someone who accompanies you may

recall something that you missed or forgot.

Write down questions to ask your doctor.

Your time with your doctor is limited, so preparing a list of questions will help you make the most

of your time together. List your questions from most important to least important in case time runs

out. Some basic questions to ask your doctor include:

Is my condition likely caused by a food allergy or another reaction?

What kinds of tests do I need?

Is my condition likely temporary or long lasting?

What types of treatment are available, and which do you recommend?

What are the alternatives to the primary approach that you're suggesting?

I have these other health conditions. How can I best manage these conditions together?

Are there any dietary restrictions that I need to follow?

Should I see a specialist? What will that cost, and will my insurance cover seeing a specialist?

Is there a generic alternative to the medicine you're prescribing me?

Do you have any printed material that I can take home with me? What websites do you recommend

visiting?

If your child is seeing the doctor for a food allergy, you may also want to ask:

Is my child likely to outgrow his or her allergy?

Are there alternatives to the food or foods that trigger my child's allergy symptoms?

How can I help keep my child with a food allergy safe at school?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions

during your appointment.

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may save time to go

over any points you want to spend more time on. Your doctor may ask:

When did you begin experiencing symptoms?

How severe were your symptoms?

How long did it take symptoms to appear after eating the food you suspect you're allergic to?

Did you take any over-the-counter allergy medications such as antihistamines, and if so, did they

help?

Does your reaction always seem to be triggered by a certain food?

How much food did you eat before the reaction?

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Was the food that caused the reaction cooked or raw?

Do you know how the food was prepared?

What, if anything, seems to improve your symptoms?

What, if anything, appears to worsen your symptoms?

What you can do in the meantime

If you suspect you have a food allergy, avoid exposure to the food altogether until your doctor's

appointment. If you do eat the food and have a mild reaction, over-the-counter antihistamines may help

relieve symptoms. If you have a more severe reaction and any signs and symptoms of anaphylaxis, seek

emergency help.

Food Ingredients and Food Allergy

Many different types of food have been identified as allergens for some people. However, misinformation

about allergic reactions to different food ingredients can sometimes cause unnecessary food avoidance.

Current scientific knowledge about some of the most common ingredients is summarized below.

Food additives

Food additives have been used for many years for five main reasons: to maintain product consistency; to

improve or maintain nutritional value; to maintain palatability and wholesomeness; to provide leavening

or control acidity and alkalinity; and to enhance flavor or impart desired color. Although most Americans

consume a wide variety of food additives daily, only a small number have been associated with reactions.

These reactions are not usually caused by an allergic response to the additive, but are examples of food

intolerance.

FD&C Yellow No. 5 (tartrazine)

FD&C Yellow No. 5 (tartrazine) is used to color beverages, candy and other foods. Scientists have

concluded the colour additive may cause hives in fewer than one out of 10,000 people. There is no

scientific evidence that FD&C Yellow No. 5 provokes asthma attacks or that people who react to aspirin

have a cross-sensitivity to it, as has been claimed in the past. Whenever FD&C Yellow No. 5 is added to

foods, it must be listed on the product label. This allows the small portion of people who may be sensitive

to FD&C Yellow No. 5 to avoid it.

Monosodium glutamate (MSG)

Monosodium glutamate (MSG) has been used for many years as a flavor enhancer. It is the sodium salt

of glutamic acid, an amino acid found naturally in the human body and in all protein-containing foods

such as cheese, vegetables, meat, and milk. The U.S. Food and Drug Administration (FDA) believes MSG

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is a safe food ingredient for the general population. MSG is not an allergen and there is conclusive

scientific evidence that MSG does not cause or exacerbate asthma. A small number of people may

experience mild and transitory symptoms to MSG. However, these short-lived responses only occur in

clinical settings upon ingestion of large doses of MSG without food, and were not reproduced in retesting.

Whenever MSG is added to food, it is listed on the label as monosodium glutamate.

Sulfites

Sulfiting agents are sometimes used to preserve the color of foods such as dried fruits and vegetables, and

to inhibit the growth of microorganisms in fermented foods such as wine. Sulfites are safe for most people.

A small segment of the population, however, has been found to develop shortness of breath or fatal shock

shortly after exposure to these preservatives. Sulfites can provoke severe asthma attacks in sulfite-

sensitive asthmatics. For that reason, in 1986 the FDA banned the use of sulfites on fresh fruits and

vegetables (except potatoes) intended to be sold or served raw to consumers. Sulfites added to all packaged

and processed foods must be listed on the product label.

COMMON FOOD ALLERGY

In adults, the most common foods that cause allergic reactions are shellfish, such as shrimp, crayfish,

lobster, and crab; nuts from trees, such as walnuts; fish; eggs; and peanuts, a legume that is one of the

chief foods that cause serious anaphylactic reactions. In highly allergic people, even minuscule amounts

of a food allergen (for example, 1/44,000 of a peanut kernel) can evoke an allergic reaction. Less sensitive

people, however, may be able to tolerate small amounts of a food to which they are allergic.

In children, the pattern is somewhat different from adults, and the most common foods that cause allergic

reactions are eggs, milk, peanuts, tree nuts, shellfish, soy, fish, and fruits, particularly tomatoes and

strawberries. Children sometimes outgrow their allergies, but adults usually do not lose theirs. Also,

children are more likely to outgrow allergies to cow's milk or soy formula than allergies to peanuts, fish,

or shrimp. Adults and children tend to react to those foods they eat more often. For example, in Japan,

allergy to rice, and in Scandinavia, allergy to codfish, is more common than elsewhere.

What is cross-reactivity?

Cross-reactivity is the occurrence of allergic reactions to foods that are chemically or otherwise related to

foods known to cause allergy in an individual. If someone has a life-threatening reaction to a certain food,

the doctor will counsel that patient to avoid related foods, which also might induce the same reaction. For

example, if a person has a history of a severe allergy to shrimp, he or she can also possibly be allergic to

crab, lobster, and crayfish.

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What is oral allergy syndrome?

The oral allergy syndrome is another type of cross-reactivity. This syndrome occurs in people who are

highly sensitive, for example, to ragweed or birch pollen. During the seasons that these allergens pollinate,

the affected individual may find that when he or she tries to eat fruits, chiefly melons and apples, a rapid

onset of itching is experienced in the mouth and throat, and the fruit cannot be eaten. The oral allergy

syndrome is also known as pollen-food allergy syndrome and is thought to be a type of contact allergy

related to the presence of proteins in certain foods that cross react with allergy-causing pollen proteins.

Oral allergy syndrome occurs in up to 50% of those who have allergic rhinitis caused by pollen. Symptoms

are immediate upon ingestion of fresh or uncooked foods and include the itching, irritation, and mild

swelling of the lips, tongue, palate, and throat. Cooked fruits and vegetables usually do not cause the

reaction. The symptoms usually go away within minutes, although up to 10% of people will develop

systemic (body-wide) symptoms, and a small number (1%-2%) may experience anaphylactic shock. Tree

nuts and peanuts tend to cause more severe reactions than other foods.

RISK FACTORS

Food allergy risk factors include:

Family history. You're at increased risk of food allergies if asthma, eczema, hives or allergies such as

hay fever are common in your family.

A past food allergy. Children may outgrow a food allergy, but in some cases it returns later in life.

Other allergies. If you're already allergic to one food, you may be at increased risk of becoming allergic

to another. Likewise, if you have other types of allergic reactions, such as hay fever or eczema, your risk

of having a food allergy is greater.

Age. Food allergies are most common in children, especially toddlers and infants. As you grow older,

your digestive system matures and your body is less likely to absorb food or food components that trigger

allergies. Fortunately, children typically outgrow allergies to milk, soy, wheat and eggs. Severe allergies

and allergies to nuts and shellfish are more likely to be lifelong.

Asthma. Asthma and food allergy commonly occur together. When they do, both food allergy and asthma

symptoms are more likely to be severe.

Factors that may increase your risk of developing an anaphylactic reaction include:

Having a history of asthma

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Being a teenager or younger

Waiting longer to use epinephrine to treat your food allergy symptoms

Not having hives or other skin symptoms

What conditions mimic food allergy?

There are many conditions that can mimic food allergy. It is critical to distinguish true food allergy from

other abnormal responses to food, that is, from food intolerance, which can occur in a variety of other

illnesses or food poisoning, which occurs when contaminated food is ingested. If a patient says to the

doctor, "I think I have a food allergy," the doctor has to consider a number of diagnoses. The possibilities

include not only food allergy but also any other diseases that have symptoms brought on by food. These

include reactions to certain chemicals in food for example, histamine or food additives, food poisoning,

several other gastrointestinal diseases, and psychological symptoms.

Histamine toxicity: Some natural substances (for example, histamine) in foods can cause reactions

resembling allergy. Histamine can reach high levels in cheese, some wines, and certain fish, particularly

tuna and mackerel. In fish, the histamine is believed to stem from bacterial contamination, especially in

fish that has not been refrigerated properly. Remember that mast cells release histamine in an allergic

reaction. If a person eats a food that contains a high level of histamine, therefore, he may develop

histamine toxicity, a response that strongly resembles an allergic reaction to food. Histamine toxicity has

been referred to as pseudo allergic fish poisoning and accounts for over one-third of seafood-related food-

borne illnesses, according to the U.S. Centre’s for Disease Control and Prevention (CDC).

Food additives: Another type of food intolerance is an adverse reaction to certain compounds that are

added to food to enhance taste, provide colour, or protect against the growth of microorganisms.

Consumption of large amounts of these additives can produce symptoms that mimic the entire range of

allergic symptoms. (Although some doctors attribute hyperactivity in children to food additives, the

evidence is not compelling, and the cause of this behavioural disorder remains uncertain.)

The compounds most frequently tied to adverse reactions that can be confused with food allergy are yellow

dye number 5, monosodium glutamate (MSG), and sulphites.

Food poisoning: Eating food that is contaminated with microorganisms, such as bacteria, and their

products, such as toxins, is the usual cause of food poisoning. Thus, the ingestion of contaminated eggs,

salad, milk, or meat can produce symptoms that mimic food allergy. Common microbes that can cause

food poisoning include the noroviruses, Campylobacter jejuni, Salmonella, Listeria

monocytogenes, Vibrio vulnificus, and E. coli Some of the symptoms of food allergy, such as abdominal

cramping, are common to food poisoning. However, food poisoning is caused by microbes, such as

bacteria, and bacterial products, such as toxins, that can contaminate meats and dairy products.

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Lactase deficiency (lactose intolerance): Another cause of food intolerance, which often is confused with

a food allergy, specifically to milk, is lactase deficiency. This common food intolerance affects at least

one out of 10 people. Lactase is an enzyme in the lining of the small intestine. This enzyme digests or

breaks down lactose, a complex sugar in milk, to simple sugars, which are then absorbed into the blood.

If a person has lactase deficiency, he does not have enough lactase to digest the lactose in most milk

products. Instead, other bacteria in the intestine use the undigested lactose, thereby producing gas.

Symptoms of lactose intolerance include bloating, abdominal pain, and diarrhoea. In a diagnostic test for

lactase deficiency, the patient ingests a specific amount of lactose. Then, by analysing a blood sample for

simple sugars, the doctor determines the patient's ability to digest the lactose and absorb the simple sugars.

A lower than normal value usually means a lactase deficiency.

Gluten-sensitive enteropathy: Intolerance to gluten occurs in a disease called gluten-sensitive

enteropathy, or celiac sprue. Gluten-sensitive enteropathy is caused by a unique abnormal immune

response to certain components of gluten, which is a constituent of the cereal grains wheat, rye, and barley.

Although sometimes referred to as an allergy to gluten, this immune response involves a branch of the

immune system that is different from the one involved in a classical food allergy. The patients have an

abnormality in the lining of the small intestine and experience diarrhoea and malabsorption, especially of

dietary fat. The treatment for this condition involves the avoidance of dietary gluten.

Other gastrointestinal diseases: Several other gastrointestinal diseases produce abdominal symptoms

(especially nausea, vomiting, diarrhoea, and pain) that are sometimes caused by food. These diseases,

therefore, can resemble food allergies. Examples include peptic ulcer, gallstones, non-ulcer dyspepsia

(which is a type of indigestion), Crohn's disease (regional enteritis), cancers of the gastrointestinal tract,

and a rare condition called eosinophilic gastroenteritis.

Psychological: Some people have a food intolerance that has a psychological origin. In these people, a

careful psychiatric evaluation may identify a traumatic event in that person's life, often during childhood,

tied to eating a particular food. The eating of that food years later, even as an adult, is associated with a

rush of symptoms that can resemble an allergic reaction to food.

COMPLICATIONS

Complications of food allergy can include:

Anaphylaxis. This is a life-threatening allergic reaction.

Atopic dermatitis (eczema). Food allergy may cause a skin reaction, such as eczema.

Migraines. Histamines, released by your immune system during an allergic reaction, have been shown to

trigger migraines in some people.

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Is It Food Allergy or Food Intolerance?

Food allergy is sometimes confused with food intolerance. To find out the difference between food allergy

and food intolerance, your healthcare professional will go through a list of possible causes for your

symptoms.

Types of Food Intolerance

Lactose intolerance

Lactose is a sugar found in milk and most milk products. Lactase is an enzyme in the lining of the gut

that breaks down or digests lactose. Lactose intolerance occurs when lactase is missing. Instead of the

enzyme breaking down the sugar, bacteria in the gut break it down, which forms gas, which in turn causes

symptoms of bloating, abdominal pain, and sometimes diarrhoea.

Lactose intolerance is uncommon in babies and young children under the age of 5 years. Because lactase

levels decline as people get older, lactose intolerance becomes more common with age. Lactose

intolerance also varies widely based on racial and ethnic background.

Your healthcare professional can use laboratory tests to find out whether your body can digest lactose.

Food additives

Another type of food intolerance is a reaction to certain products that are added to food to enhance taste,

add color, or protect against the growth of microbes. Several compounds such as MSG (monosodium

glutamate) and sulfites are tied to reactions that can be confused with food allergy.

MSG is a flavor enhancer. When taken in large amounts, it can cause some of the following: Flushing,

Sensations of warmth, Headache, Chest discomfort. These passing reactions occur rapidly after eating

large amounts of food to which MSG has been added.

Sulphites are found in food for several reasons: They have been added to increase crispness or prevent

mould growth. They occur naturally in the food. They have been generated during the winemaking

process. Sulphites can cause breathing problems in people with asthma. The Food and Drug

Administration (FDA) has banned sulphites as spray-on preservatives for fresh fruits and vegetables.

When sulphites are present in foods, they are listed on ingredient labels.

Gluten intolerance

Gluten is a part of wheat, barley, and rye. Gluten intolerance is associated with celiac disease, also called

gluten-sensitive enteropathy. This disease develops when the immune system responds abnormally to

gluten. This abnormal response does not involve IgE antibody and is not considered a food allergy.

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Other

Several other conditions, such as ulcers and cancers of the GI tract, cause some of the same symptoms as

food allergy. These symptoms, which include vomiting, diarrhoea, and cramping abdominal pain, become

worse when you eat.

TESTS AND DIAGNOSIS

There's no standard test used to confirm or rule out a food allergy. Your doctor will consider a number of

things before making a diagnosis. The following may help determine if you're allergic to a food or if your

symptoms are caused by something else:

Description of your symptoms. Be prepared to tell your doctor a history of your symptoms — which

foods, and how much, seem to cause problems — and whether you have a family history of food allergies

or other allergies.

Physical examination. A careful exam can often identify or exclude other medical problems.

Food diary. Your doctor may ask you to keep a food diary of your eating habits, symptoms and

medications to pinpoint the problem.

Skin test. A skin prick test can determine your reaction to a particular food. In this test, a small amount

of the suspected food is placed on the skin of your forearm or back. Your skin is then pricked with a

needle to allow a tiny amount of the substance beneath your skin surface.

If you're allergic to a particular substance being tested, you develop a raised bump or reaction. Keep in

mind, a positive reaction to this test alone isn't enough to confirm a food allergy.

Elimination diet. You may be asked to eliminate suspect foods for a week or two and then add the food

items back into your diet one at a time. This process can help link symptoms to specific foods. However,

this isn't a fool proof method.

Psychological factors as well as physical factors can come into play. For example, if you think you're

sensitive to a food, a response could be triggered that may not be a true allergic one. If you've had a severe

reaction to a food in the past, this method may not be safe.

Blood test. A blood test can measure your immune system's response to particular foods by checking the

amount of allergy-type antibodies in your bloodstream known as immunoglobulin E (IgE) antibodies. For

this test, a blood sample taken in your doctor's office is sent to a medical laboratory, where different foods

can be tested. However, these blood tests aren't always accurate.

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Oral food challenge. During this test, done in the doctor's office, you'll be given small but increasing

amounts of the suspect food. If you don't have a reaction during this test, you may be able to include this

food in your diet again.

TREATMENT AND DRUGS

The only way to avoid an allergic reaction is to avoid the foods that cause signs and symptoms. However,

despite your best efforts, you may come into contact with a food that causes a reaction.

For a minor allergic reaction, in these cases, OTC or prescribed antihistamines such as diphenhydramine

(Benadryl) may help reduce symptoms. These drugs can be taken after exposure to an allergy-causing

food to help relieve itching or hives. However, antihistamines can't treat a severe allergic reaction.

For a severe allergic reaction, you may need an emergency injection of epinephrine and a trip to the

emergency room. Many people with allergies carry an epinephrine auto injector (EpiPen, Twinjet, Auvi-

Q). This device is a combined syringe and concealed needle that injects a single dose of medication when

pressed against your thigh.

If your doctor has prescribed an epinephrine auto injector:

Be sure you know how to use the auto injector. Also, make sure the people closest to you know

how to administer the drug — if they're with you in an anaphylactic emergency, they could save

your life.

Carry it with you at all times. It may be a good idea to keep an extra auto injector in your car or

in your desk at work.

Always be sure to replace epinephrine before its expiration date or it may not work properly.

Dietary avoidance: Avoiding the offending allergen in the diet is the primary treatment of food allergy.

Once a food to which the patient is sensitive has been identified, the food must be removed from the diet.

To do this, affected people need to read lengthy, detailed lists of ingredients on the label for each food

they consider eating. Many allergy-producing foods such as peanuts, eggs, and milk appear in foods that

are not ordinarily associated with them. For example, peanuts often are used as protein supplements, eggs

are found in some salad dressings, and milk is in bakery products. The FDA requires that the ingredients

in a food be listed on its label. People can avoid most of the foods to which they are sensitive if they

carefully read the labels on foods and, when in restaurants, avoid ordering foods that might contain

ingredients to which they are allergic.

Treating an anaphylactic reaction: People with severe food allergies must be prepared to treat an

anaphylactic reaction. Even those who know a lot about their own allergies can either make an error or be

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served food that does not comply with their instructions. To protect themselves, people who have had

anaphylactic reactions to a food should wear medical alert bracelets or necklaces stating that they have a

food allergy and that they are subject to severe reactions. These individuals also always should carry a

syringe of adrenaline (epinephrine [EpiPen, Auvi-Q]), obtained by prescription from their doctors, and be

prepared to self-administer it if they think they are developing an allergic reaction. They then should

immediately seek medical help by either calling the rescue squad or having themselves transported to an

emergency room.

Treating other symptoms of food allergy: Several medications are available for treating the other

symptoms of food allergy. For example, antihistamines can relieve gastrointestinal symptoms, hives,

sneezing, and a runny nose. Bronchodilators can relieve the symptoms of asthma. These medications are

taken after a person inadvertently has ingested a food to which he is allergic. They are not effective,

however, in preventing an allergic reaction when taken prior to eating the food. In fact, no medication in

any form is available to reliably prevent an allergic reaction to a certain food before eating that food.

Experimental treatments

While there's ongoing research to find better treatments to reduce food allergy symptoms and prevent

allergy attacks, there isn't any proven treatment that can prevent or completely relieve symptoms.

Unfortunately, allergy shots (immunotherapy), a series of injections used to reduce the effect of other

allergies such as hay fever, aren't effective for treating food allergies.

Two treatments being studied are:

Anti-IgE therapy. The medication omalizumab (Xolair) interferes with the body's ability to use

IgE. The drug is currently being studied for treatment of allergic asthma and food allergies.

However, this treatment is still considered experimental, and more research needs to be done on

the drug's long-term safety. It has been associated with a potential increased risk of anaphylaxis.

Oral immunotherapy. Researchers have been studying the use of oral immunotherapy (OIT) as

a treatment for food allergy. Small doses of the food you're allergic to are swallowed or placed

under your tongue (sublingual). The dose of the allergy-provoking food is gradually increased.

Initial results look promising, even in people with peanut allergy. But more research needs to be

done to ensure that this treatment is safe.

LIFESTYLE AND HOME REMEDIES

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One of the keys to preventing an allergic reaction is to completely avoid the food that causes your

symptoms.

Don't assume. Always read food labels to make sure they don't contain an ingredient you're allergic to.

Even if you think you know what's in a food, check the label. Ingredients sometimes change.

Food labels are required to clearly list whether they contain any common food allergens. Read food labels

carefully to avoid the most common sources of food allergens: milk, eggs, peanuts, tree nuts, fish,

shellfish, soy and wheat.

When in doubt, say no thanks. At restaurants and social gatherings, you're always taking a risk that you

might eat a food you're allergic to. Many people don't understand the seriousness of an allergic food

reaction and may not realize that a tiny amount of a food can cause a severe reaction in some people. If

you have any suspicion at all that a food may contain something you're allergic to, steer clear.

Involve caregivers. If your child has a food allergy, enlist the help of relatives, baby sitters, teachers and

other caregivers. Make sure they understand how important it is for your child to avoid the allergy-causing

food and that they know what to do in an emergency.

It's also important to let caregivers know what steps they can take to prevent a reaction in the first place,

such as careful hand-washing and cleaning any surfaces that might have come in contact with the allergy-

causing food.

ALTERNATIVE MEDICINE

Research on alternative food allergy treatments is limited. However, many people do try them and claim

that certain treatments help.

Herbal remedies. A few small studies of herbal remedies have shown some benefit in reducing symptoms

and preventing anaphylaxis, including some Chinese medicine formulas. However, there's no reliable

proof yet that these work.

In addition, concerns exist about the quality of some herbal preparations from China. If you do take an

herbal remedy, be sure to tell your doctor about it. It may affect test results or interact with other

medications you take.

Acupuncture and acupressure. There's little academic research on acupuncture for food allergies, and

the studies that do exist don't show a clear benefit from these techniques. If you decide to try one of these

treatments, be sure you work with an experienced and certified provider.

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COPING AND SUPPORT

A food allergy can be challenging and a source of ongoing concern. Having a good source of information

and the opportunity to discuss the condition with others who share your concerns can be very helpful. A

number of Internet sites and non-profit organizations offer information and forums for discussing food

allergies. Some are specifically for parents of children with food allergies. The Food Allergy Research &

Education website can direct you to support groups and events in your area. Many people find it helpful

to talk to others who are dealing with the same challenges.

PREVENTION

The best way to prevent an allergic reaction is to know and avoid foods that cause signs and symptoms.

For some people, this is a mere inconvenience, but others find it a greater hardship. Also, some foods —

when used as ingredients in certain dishes — may be well hidden. This is especially true in restaurants

and in other social settings.

If you know you have a food allergy, follow these steps:

Know what you're eating and drinking. Be sure to read food labels carefully.

If you have already had a severe reaction, wear a medical alert bracelet or necklace that lets

others know that you have a food allergy in case you have a reaction and you're unable to

communicate.

Talk with your doctor about prescribing emergency epinephrine. You may need to carry an

epinephrine auto injector (EpiPen, Twinject, Auvi-Q) if you're at risk of a severe allergic reaction.

Be careful at restaurants. Be certain your server or chef is aware that you absolutely can't eat the

food you're allergic to, and you need to be completely certain that the meal you order doesn't

contain it. Also, make sure food isn't prepared on surfaces or in pans that contained any of the food

you're allergic to.

Don't be reluctant to make your needs known. Restaurant staff members are usually more than happy to

help when they clearly understand your request.

If your child has a food allergy, take these precautions to ensure his or her safety:

Notify key people that your child has a food allergy. Talk with child care providers, school

personnel, parents of your child's friends and other adults who regularly interact with your child.

Emphasize that an allergic reaction can be life-threatening and requires immediate action. Make

sure that your child also knows to ask for help right away if he or she reacts to food.

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Explain food allergy symptoms. Teach the adults who spend time with your child how to

recognize signs and symptoms of an allergic reaction.

Write an action plan. Your plan should describe how to care for your child when he or she has

an allergic reaction to food. Provide a copy of the plan to your child's school nurse and others who

care for and supervise your child.

Have your child wear a medical alert bracelet or necklace. This alert lists your child's allergy

symptoms and explains how others can provide first aid in an emergency.

SPECIAL PROGRAM AND RESOURCE AT THE INSTITUTE

The Centre for Integrative Medicine

The Centre for Integrative Medicine at the Jaffe Food Allergy Institute focuses on traditional Chinese

medicine treatments for children and adults. This centre seeks to provide additional health care options

for patients with multiple allergic conditions who may be interested in complementary and alternative

medicine therapies to be used in conjunction with an established management plan from their traditional

physicians. Traditional Chinese medicine, used in China and other Asian countries for centuries, is now

part of mainstream medicine and is beginning to play a larger role in the American health care system.

The Centre will facilitate clinical research and education and offer treatment options such as herbal

remedies, acupuncture, and acupressure for allergic conditions such as eczema associated with food and

environmental allergies.

The EMPOWER Program

The EMPOWER (Enhancing, Managing, and Promoting Well-being and Resiliency) Program at the Jaffe

Institute is staffed by professionals with particular expertise in managing behavioral and emotional issues

in children with food allergy and their families. The program offers individual consultation, referral

services and group treatment to patients and their families. As with other Jaffe Institute centres, an

important mission of the EMPOWER program is to engage in research efforts. We aim to better

understand the extent, reasons for, and management of distress in food-allergic individuals and their

families, and we aim to help patients and families improve coping abilities and develop enhanced

resilience. The program’s focus on enhancing resiliency is unique, and we hope that it will serve as a

model for providing multidisciplinary, holistic care within the Jaffe Food Allergy Institute and beyond. If

you have questions or concerns about the emotional aspects of living with food allergy or with managing

your child’s allergies, please discuss this with your doctor or ask about our EMPOWER program. Also,

whether or not you have questions or worries, please consider participating in the EMPOWER program’s

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research and screening efforts. You can help us improve our understanding of our patients’ and families’

concerns and strengths. Together, we may discover ways to enhance coping with food allergies.

The Centre for Eosinophilic Disorders

Eosinophilic esophagitis (EoE) is a disease of theesophagus (the tube that connects the mouth to the

stomach) caused by food allergies. Certain foods trigger EoE by causing allergy cells and other white

blood cells, called eosinophil, to migrate to the esophagus. Symptoms may include stomach pain,

vomiting, heartburn, difficulty swallowing, poor appetite, food refusal, and poor growth. These symptoms

can mimic acid-induced reflux; however, they usually do not improve with antacid therapies that are often

used to treat reflux. Treatment for EoE includes dietary modifications and other medical therapies. Special

expertise is needed in treating this condition, since food allergens that trigger EOE work in a very special

way, different from what has been traditionally known. If you have or your child has symptoms suggestive

of EOE, please discuss them with your doctor, who may refer you to our Mount Sinai Centre for

Eosinophilic Disorders at the Jaffe Food Allergy Institute. At the Mount Sinai Centre for Eosinophilic

Disorders, you will encounter a caring team of professionals who have specialized knowledge and

expertise in diagnosing and treating EOE and other eosinophilic gastrointestinal disorders. The team is

multidisciplinary, consisting of a gastroenterologist, allergists, a dietician and a psychiatrist. The Mount

Sinai Center for Eosinophilic Disorders is also involved in research aimed at developing optimal

treatments for children and adults living with EOE.

Food Allergy Research at NIAID

The National Institute of Allergy and Infectious Diseases (NIAID) is the lead institute for food allergy

research at the National Institutes of Health. NIAID supports basic and preclinical research in allergy and

immunology that provides an increasingly better understanding of the immune system and how, in certain

people, food elicits an allergic reaction. NIAID also conducts clinical trials that are attempting to change

the body’s immune response so that it does not trigger an allergic reaction to food. These trials are either

prevention trials or treatment trials.

• Prevention trials attempt to prevent allergies from developing in young children who are not yet allergic

to a food.

• Treatment trials try to train the immune systems of people who are already allergic to a food not to react

to the specific food.

Both treatment and prevention strategies attempt to induce a state of immunological tolerance to a food.

Current food allergy clinical trials funded by NIAID can be found on the Web site ClinicalTrials.gov by

searching for “NIAID” and “food allergy.”

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SUMMARY

Food allergy is caused by immune reactions to foods, sometimes in individuals or families predisposed to

allergies. A number of foods, especially shellfish, milk, eggs, peanuts, and fruit can cause allergic

reactions (notably hives, asthma, abdominal symptoms, light-headedness, and anaphylaxis) in adults or

children. When a food allergy is suspected, a medical evaluation is the key to proper management.

It is important to distinguish a true food allergy from other abnormal responses to food, that is, food

intolerances, which actually are far more common than food allergy. Once the diagnosis of food allergy

is made (primarily by the medical history) and the allergen is identified (usually by skin tests), the

treatment basically is to avoid the offending food. People with food allergies should work with their

physicians and become knowledgeable about allergies and how they are diagnosed and treated.

REFERENCE

1) Evaluation of Allergen city of Genetically Modified Foods. Report of a Joint FAO/WHO Expert

Consultation of Allergenicity of Foods Derived from Biotechnology, January 2001. Food and

Agriculture Organization of the United Nations (FAO), Rome, Italy; World Health Organization.

2) Schwartz, H.J. Asthma and food additives. In Food Allergy: Adverse Reactions to Foods and Food

Additives; Metcalfe, DD, Sampson, HA, Simon, RA, [Eds], Cambridge, MA, Blackwell Science,

2000: 411-416.

3) Lemke, P.J., Ta y l o r, S.L. Allergic reactions and food intolerances. In: Kotsonis, F.N., Macke y,

M., Hjelle, J., eds. Nutritional toxicology. New York, Raven Press; 1994:117-37.

4) Food and Agriculture Organization (FAO). Report of the FAO Technical Consultation on food

allergies. Rome, Italy. November 13-14, 1995.

5) Novembre E, Cianferoni A, Bernardini R, Mugnaini L, Caffarelli C, Cavagni G, et al. Anaphylaxis

in children: Clinical and allergologic features. Paediatrics 1998; 101(4):E8.

6) Fug sang G, Madsen G, Hal ken S, et al. Adverse reactions to food additives in children with atopic

symptoms. Allergy 1994; 49:31-7.