What food allergies cause anaphylactic shock

Food allergies are divided into 3 types, depending on symptoms and when they occur.

  1. non-IgE-mediated food allergy – these allergic reactions aren’t caused by immunoglobulin E, but by other cells in the immune system. This type of allergy is often hard to diagnose as symptoms take much longer to develop (up to several hours).
  2. IgE-mediated food allergy – the most common type, triggered by the immune system producing an antibody called immunoglobulin E (IgE). Symptoms occur a few seconds or minutes after eating. There’s a greater risk of anaphylaxis with this type of allergy.

    What food allergies cause anaphylactic shock

  3. mixed IgE and non-IgE-mediated food allergies – some people may experience symptoms from both types.

Read more information about the symptoms of a food allergy.

Oral allergy syndrome (pollen-food syndrome)

Some people experience itchiness in their mouth and throat, sometimes with mild swelling, immediately after eating unused fruit or vegetables.

What food allergies cause anaphylactic shock

This is known as oral allergy syndrome.

Oral allergy syndrome is caused by allergy antibodies mistaking certain proteins in unused fruits, nuts or vegetables for pollen.

Oral allergy syndrome generally doesn’t cause severe symptoms, and it’s possible to deactivate the allergens by thoroughly cooking any fruit and vegetables.

The Allergy UK website has more information.


What causes food allergies?

Food allergies happen when the immune system – the body’s defence against infection – mistakenly treats proteins found in food as a threat.

As a result, a number of chemicals are released. It’s these chemicals that cause the symptoms of an allergic reaction.

Almost any food can cause an allergic reaction, but there are certain foods that are responsible for most food allergies.

Foods that most commonly cause an allergic reaction are:

  1. tree nuts
  2. milk
  3. eggs
  4. shellfish
  5. peanuts
  6. fish
  7. some fruit and vegetables

Most children that own a food allergy will own experienced eczema during infancy.

The worse the child’s eczema and the earlier it started, the more likely they are to own a food allergy.

It’s still unknown why people develop allergies to food, although they often own other allergic conditions, such as asthma, hay fever and eczema.

Read more information about the causes and risk factors for food allergies.


When to seek medical advice

If you ponder you or your kid may own a food allergy, it’s extremely significant to enquire for a professional diagnosis from your GP. They can then refer you to an allergy clinic if appropriate.

Many parents mistakenly assume their child has a food allergy when their symptoms are actually caused by a completely different condition.

Commercial allergy testing kits are available, but using them isn’t recommended.

Numerous kits are based on unsound scientific principles. Even if they are dependable, you should own the results looked at by a health professional.

Read more about diagnosing food allergies.


Anaphylaxis

In the most serious cases, a person has a severe allergic reaction (anaphylaxis), which can be life threatening.

Call 999 if you ponder someone has the symptoms of anaphylaxis, such as:

  1. trouble swallowing or speaking
  2. breathing difficulties
  3. feeling dizzy or faint

Ask for an ambulance and tell the operator you ponder the person is having a severe allergic reaction.


Treatment

The best way to prevent an allergic reaction is to identify the food that causes the allergy and avoid it.

Research is currently looking at ways to desensitise some food allergens, such as peanuts and milk, but this is not an established treatment in the NHS.

Read more about identifying foods that cause allergies (allergens).

Avoid making any radical changes, such as cutting out dairy products, to your or your child’s diet without first talking to your GP. For some foods, such as milk, you may need to speak to a dietitian before making any changes.

Antihistamines can assist relieve the symptoms of a mild or moderate allergic reaction.

What food allergies cause anaphylactic shock

A higher dose of antihistamine is often needed to control acute allergic symptoms.

Adrenaline is an effective treatment for more severe allergic symptoms, such as anaphylaxis.

People with a food allergy are often given a device known as an auto-injector pen, which contains doses of adrenaline that can be used in emergencies.

Read more about the treatment of food allergies.


What is food intolerance?

A food intolerance isn’t the same as a food allergy.

People with food intolerance may own symptoms such as diarrhoea, bloating and stomach cramps. This may be caused by difficulties digesting certain substances, such as lactose.

However, no allergic reaction takes place.

Important differences between a food allergy and a food intolerance include:

  1. you need to eat a larger quantity of food to trigger an intolerance than an allergy
  2. the symptoms of a food intolerance generally happen several hours after eating the food
  3. a food intolerance is never life threatening, unlike an allergy

Read more about food intolerance.

Sheet final reviewed: 15 April 2019
Next review due: 15 April 2022

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Watch a video on Reducing the Risks of Food Allergies.

What food allergies cause anaphylactic shock

Each year, millions of Americans own allergic reactions to food. Although most food allergies cause relatively mild and minor symptoms,some food allergies can cause severe reactions, and may even be life-threatening.

There is no cure for food allergies. Strict avoidance of food allergens — and early recognition and management of allergic reactions to food — are significant measures to prevent serious health consequences.

Know the Symptoms

Symptoms of food allergies typically appear from within a few minutes to 2 hours after a person has eaten the food to which he or she is allergic.

Allergic reactions can include:

  1. Loss of consciousness
  2. Tingling or itchy sensation in the mouth
  3. Hives
  4. Fish (e.g., bass, flounder, cod)
  5. Abdominal cramps
  6. Peanuts
  7. Tree nuts (e.g., almonds, walnuts, pecans)
  8. Eggs
  9. Face, tongue, or lip swelling
  10. Crustacean shellfish (e.g., crab, lobster, shrimp)
  11. Dizziness and/or lightheadedness
  12. Vomiting and/or diarrhea
  13. Swelling of the throat and vocal cords
  14. Wheat
  15. Flushed skin or rash
  16. Coughing or wheezing
  17. Difficulty breathing
  18. Milk
  19. Soybeans

About Other Allergens

Persons may still be allergic to — and own serious reactions to — foods other than the eight foods identified by the law.

So, always be certain to read the food label’s ingredient list carefully to avoid the food allergens in question.

What Are Major Food Allergens?

While more than 160 foods can cause allergic reactions in people with food allergies, the law identifies the eight most common allergenic foods. These foods account for 90 percent of food allergic reactions, and are the food sources from which numerous other ingredients are derived.

The eight foods identified by the law are

  • severe lowering of blood pressure and shock (“anaphylactic shock”)
  • Fish (e.g., bass, flounder, cod)
  • Milk
  • 150 deaths
  • Tree nuts (e.g., almonds, walnuts, pecans)
  • Contact MedWatch, FDA’s Safety Information and Adverse Event Reporting Program, at 800-332-1088, or file a MedWatch voluntary report at www.fda.gov/MedWatch
  • 30,000 emergency room visits
  • suffocation by swelling of the throat
  • Crustacean shellfish (e.g., crab, lobster, shrimp)
  • constricted airways in the lungs
  • Peanuts
  • Eggs
  • Soybeans
  • 2,000 hospitalizations
  • Wheat
  • Contact the consumer complaint coordinator in their area.

    The list of FDA consumer complaint coordinators is available at www.fda.gov/Safety/ReportaProblem/ConsumerComplaintCoordinators/default

These eight foods, and any ingredient that contains protein derived from one or more of them, are designated as “major food allergens’ by FALCPA.

FDA’s Role: Labeling

To assist Americans avoid the health risks posed by food allergens, FDA enforces the Food Allergen Labeling and Consumer Protection Act of 2004 (the Act). The Act applies to the labeling of foods regulated by FDA which includes every foods except poultry, most meats, certain egg products, and most alcoholic beverages which are regulated by other Federal agencies.

The Act requires that food labels must clearly identify the food source names of any ingredients that are one of the major food allergens or contain any protein derived from a major food allergen.

As a result, food labels assist allergic consumers identify offending foods or ingredients so they can more easily avoid them.

Food Allergen “Advisory” Labeling

FALCPA’s labeling requirements do not apply to the potential or unintentional presence of major food allergens in foods resulting from “cross-contact” situations during manufacturing, e.g., because of shared equipment or processing lines. In the context of food allergens, “cross-contact” occurs when a residue or trace quantity of an allergenic food becomes incorporated into another food not intended to contain it.

FDA guidance for the food industry states that food allergen advisory statements, e.g., “may contain [allergen]” or “produced in a facility that also uses [allergen]” should not be used as a substitute for adhering to current excellent manufacturing practices and must be truthful and not misleading. FDA is considering ways to best manage the use of these types of statements by manufacturers to better inform consumers.

Severe Food Allergies Can Be Life-Threatening

Following ingestion of a food allergen(s), a person with food allergies can experience a severe, life-threatening allergic reaction called anaphylaxis.

This can lead to:

  1. severe lowering of blood pressure and shock (“anaphylactic shock”)
  2. constricted airways in the lungs
  3. suffocation by swelling of the throat

Each year in the U.S., it is estimated that anaphylaxis to food results in:

  1. 150 deaths
  2. 30,000 emergency room visits
  3. 2,000 hospitalizations
  4. Contact MedWatch, FDA’s Safety Information and Adverse Event Reporting Program, at 800-332-1088, or file a MedWatch voluntary report at www.fda.gov/MedWatch
  5. Contact the consumer complaint coordinator in their area.

    The list of FDA consumer complaint coordinators is available at www.fda.gov/Safety/ReportaProblem/ConsumerComplaintCoordinators/default

Prompt istration of epinephrine by autoinjector (e.g., Epi-pen) during early symptoms of anaphylaxis may assist prevent these serious consequences.

Reporting Adverse Effects and Labeling Concerns

If you ponder that you or a family member has an injury or illness that you believe is associated with having eaten a specific food, including individuals with food allergies and those with celiac disease, contact your healthcare provider immediately.

Also, report the suspected foodborne illness to FDA in either of these ways:

Individuals can report a problem with a food or its labeling, such as potential misuse of “gluten-free” claims, to FDA in either of these ways:

These eight foods, and any ingredient that contains protein derived from one or more of them, are designated as “major food allergens’ by FALCPA.

FDA’s Role: Labeling

To assist Americans avoid the health risks posed by food allergens, FDA enforces the Food Allergen Labeling and Consumer Protection Act of 2004 (the Act).

The Act applies to the labeling of foods regulated by FDA which includes every foods except poultry, most meats, certain egg products, and most alcoholic beverages which are regulated by other Federal agencies. The Act requires that food labels must clearly identify the food source names of any ingredients that are one of the major food allergens or contain any protein derived from a major food allergen.

As a result, food labels assist allergic consumers identify offending foods or ingredients so they can more easily avoid them.

Food Allergen “Advisory” Labeling

FALCPA’s labeling requirements do not apply to the potential or unintentional presence of major food allergens in foods resulting from “cross-contact” situations during manufacturing, e.g., because of shared equipment or processing lines.

In the context of food allergens, “cross-contact” occurs when a residue or trace quantity of an allergenic food becomes incorporated into another food not intended to contain it. FDA guidance for the food industry states that food allergen advisory statements, e.g., “may contain [allergen]” or “produced in a facility that also uses [allergen]” should not be used as a substitute for adhering to current excellent manufacturing practices and must be truthful and not misleading. FDA is considering ways to best manage the use of these types of statements by manufacturers to better inform consumers.

Severe Food Allergies Can Be Life-Threatening

Following ingestion of a food allergen(s), a person with food allergies can experience a severe, life-threatening allergic reaction called anaphylaxis.

This can lead to:

  1. severe lowering of blood pressure and shock (“anaphylactic shock”)
  2. constricted airways in the lungs
  3. suffocation by swelling of the throat

Each year in the U.S., it is estimated that anaphylaxis to food results in:

  1. 150 deaths
  2. 30,000 emergency room visits
  3. 2,000 hospitalizations
  4. Contact MedWatch, FDA’s Safety Information and Adverse Event Reporting Program, at 800-332-1088, or file a MedWatch voluntary report at www.fda.gov/MedWatch
  5. Contact the consumer complaint coordinator in their area.

    The list of FDA consumer complaint coordinators is available at www.fda.gov/Safety/ReportaProblem/ConsumerComplaintCoordinators/default

Prompt istration of epinephrine by autoinjector (e.g., Epi-pen) during early symptoms of anaphylaxis may assist prevent these serious consequences.

Reporting Adverse Effects and Labeling Concerns

If you ponder that you or a family member has an injury or illness that you believe is associated with having eaten a specific food, including individuals with food allergies and those with celiac disease, contact your healthcare provider immediately.

Also, report the suspected foodborne illness to FDA in either of these ways:

Individuals can report a problem with a food or its labeling, such as potential misuse of “gluten-free” claims, to FDA in either of these ways:

  • Persons with a known food allergy who start experiencing symptoms while, or after, eating a food should initiate treatment immediately, and go to a nearby emergency room if symptoms progress.
  • Contact MedWatch, FDA’s Safety Information and Adverse Event Reporting Program, at 800-332-1088, or file a MedWatch voluntary report at www.fda.gov/MedWatch
  • Contact the consumer complaint coordinator in their area.

    The list of FDA consumer complaint coordinators is available at www.fda.gov/Safety/ReportaProblem/ConsumerComplaintCoordinators/default

  • In parentheses following the name of the ingredient.
    Examples: “lecithin (soy),” “flour (wheat),” and “whey (milk)”

    OR

  • Persons found to own a food allergy should be taught to read labels and avoid the offending foods.

    What food allergies cause anaphylactic shock

    They should also be taught, in case of accidental ingestion, to recognize the early symptoms of an allergic reaction, and be properly educated on — and armed with — appropriate treatment measures.

  • Immediately after or next to the list of ingredients in a “contains” statement.
    Example: “Contains Wheat, Milk, and Soy.”

What To Do If Symptoms Occur

The appearance of symptoms after eating food may be a sign of a food allergy. The food(s) that caused these symptoms should be avoided, and the affected person, should contact a doctor or health care provider for appropriate testing and evaluation.

  1. Persons with a known food allergy who start experiencing symptoms while, or after, eating a food should initiate treatment immediately, and go to a nearby emergency room if symptoms progress.
  2. Persons found to own a food allergy should be taught to read labels and avoid the offending foods.

    They should also be taught, in case of accidental ingestion, to recognize the early symptoms of an allergic reaction, and be properly educated on — and armed with — appropriate treatment measures.

  3. In parentheses following the name of the ingredient.
    Examples: “lecithin (soy),” “flour (wheat),” and “whey (milk)”

    OR

  4. Immediately after or next to the list of ingredients in a “contains” statement.
    Example: “Contains Wheat, Milk, and Soy.”

Mild Symptoms Can Become More Severe

Initially mild symptoms that happen after ingesting a food allergen are not always a measure of mild severity.

In fact, if not treated promptly, these symptoms can become more serious in a extremely short quantity of time, and could lead to anaphylaxis.

How Major Food Allergens Are Listed

The law requires that food labels identify the food source names of every major food allergens used to make the food. This requirement is met if the common or usual name of an ingredient (e.g., buttermilk) that is a major food allergen already identifies that allergen’s food source name (i.e., milk). Otherwise, the allergen’s food source name must be declared at least once on the food label in one of two ways.

The name of the food source of a major food allergen must appear:


What To Do If Symptoms Occur

The appearance of symptoms after eating food may be a sign of a food allergy.

The food(s) that caused these symptoms should be avoided, and the affected person, should contact a doctor or health care provider for appropriate testing and evaluation.

  1. Persons with a known food allergy who start experiencing symptoms while, or after, eating a food should initiate treatment immediately, and go to a nearby emergency room if symptoms progress.
  2. Persons found to own a food allergy should be taught to read labels and avoid the offending foods.

    They should also be taught, in case of accidental ingestion, to recognize the early symptoms of an allergic reaction, and be properly educated on — and armed with — appropriate treatment measures.

  3. In parentheses following the name of the ingredient.
    Examples: “lecithin (soy),” “flour (wheat),” and “whey (milk)”

    OR

  4. Immediately after or next to the list of ingredients in a “contains” statement.
    Example: “Contains Wheat, Milk, and Soy.”

Mild Symptoms Can Become More Severe

Initially mild symptoms that happen after ingesting a food allergen are not always a measure of mild severity.

In fact, if not treated promptly, these symptoms can become more serious in a extremely short quantity of time, and could lead to anaphylaxis.

How Major Food Allergens Are Listed

The law requires that food labels identify the food source names of every major food allergens used to make the food. This requirement is met if the common or usual name of an ingredient (e.g., buttermilk) that is a major food allergen already identifies that allergen’s food source name (i.e., milk).

Otherwise, the allergen’s food source name must be declared at least once on the food label in one of two ways.

The name of the food source of a major food allergen must appear:

  • In parentheses following the name of the ingredient.
    Examples: “lecithin (soy),” “flour (wheat),” and “whey (milk)”

    OR

  • Immediately after or next to the list of ingredients in a “contains” statement.
    Example: “Contains Wheat, Milk, and Soy.”

Other Resources

In most cases, people with allergies develop mild to moderate symptoms, such as watery eyes, a runny nose or a rash.

What food allergies cause anaphylactic shock

But sometimes, exposure to an allergen can cause a life-threatening allergic reaction known as anaphylaxis. This severe reaction happens when an over-release of chemicals puts the person into shock. Allergies to food, insect stings, medications and latex are most frequently associated with anaphylaxis.

A second anaphylactic reaction, known as a biphasic reaction, can happen as endless as 12 hours after the initial reaction.

Call 911 and get to the nearest emergency facility at the first sign of anaphylaxis, even if you own already istered epinephrine, the drug used to treat severe allergic reactions.

Just because an allergic person has never had an anaphylactic reaction in the past to an offending allergen, doesn’t mean that one won’t happen in the future. If you own had an anaphylactic reaction in the past, you are at risk of future reactions.

Severe allergic reaction

Anaphylaxis
Angioedema of the face such that the boy cannot open his eyes. This reaction was caused by an allergen exposure.
Specialty Allergy and immunology
Symptoms Itchy rash, throat swelling, shortness of breath, lightheadedness[1]
Usual onset Over minutes to hours[1]
Causes Insect bites, foods, medications[1]
Diagnostic method Based on symptoms[2]
Differential diagnosis Allergic reaction, angioedema, asthma exacerbation, carcinoid syndrome[2]
Treatment Epinephrine, intravenous fluids[1]
Frequency 0.05–2%[3]

Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death.[4][5] It typically causes more than one of the following: an itchy rash, throat or tongue swelling, shortness of breath, vomiting, lightheadedness, and low blood pressure.[1] These symptoms typically come on over minutes to hours.[1]

Common causes include insect bites and stings, foods, and medications.[1] Other causes include latex exposure and exercise.[1] Additionally, cases may happen without an obvious reason.[1] The mechanism involves the release of mediators from certain types of white blood cells triggered by either immunologic or non-immunologic mechanisms.[6] Diagnosis is based on the presenting symptoms and signs after exposure to a potential allergen.[1]

The primary treatment of anaphylaxis is epinephrineinjection into a muscle, intravenous fluids, and positioning the person flat.[1][7] Additional doses of epinephrine may be required.[1] Other measures, such as antihistamines and steroids, are complementary.[1] Carrying an epinephrine autoinjector and identification regarding the condition is recommended in people with a history of anaphylaxis.[1]

Worldwide, 0.05–2% of the population is estimated to experience anaphylaxis at some point in life.[3] Rates appear to be increasing.[3] It occurs most often in young people and females.[7][8] Of people who go to a hospital with anaphylaxis in the United States about 99.7% survive.[9] The term comes from the Ancient Greek: ἀνά, romanized: ana, lit. 'against', and the Ancient Greek: φύλαξις, romanized: phylaxis, lit. 'protection'.[10]

Other Resources

In most cases, people with allergies develop mild to moderate symptoms, such as watery eyes, a runny nose or a rash.

But sometimes, exposure to an allergen can cause a life-threatening allergic reaction known as anaphylaxis. This severe reaction happens when an over-release of chemicals puts the person into shock. Allergies to food, insect stings, medications and latex are most frequently associated with anaphylaxis.

A second anaphylactic reaction, known as a biphasic reaction, can happen as endless as 12 hours after the initial reaction.

Call 911 and get to the nearest emergency facility at the first sign of anaphylaxis, even if you own already istered epinephrine, the drug used to treat severe allergic reactions.

What food allergies cause anaphylactic shock

Just because an allergic person has never had an anaphylactic reaction in the past to an offending allergen, doesn’t mean that one won’t happen in the future. If you own had an anaphylactic reaction in the past, you are at risk of future reactions.

Severe allergic reaction

Anaphylaxis
Angioedema of the face such that the boy cannot open his eyes. This reaction was caused by an allergen exposure.
Specialty Allergy and immunology
Symptoms Itchy rash, throat swelling, shortness of breath, lightheadedness[1]
Usual onset Over minutes to hours[1]
Causes Insect bites, foods, medications[1]
Diagnostic method Based on symptoms[2]
Differential diagnosis Allergic reaction, angioedema, asthma exacerbation, carcinoid syndrome[2]
Treatment Epinephrine, intravenous fluids[1]
Frequency 0.05–2%[3]

Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death.[4][5] It typically causes more than one of the following: an itchy rash, throat or tongue swelling, shortness of breath, vomiting, lightheadedness, and low blood pressure.[1] These symptoms typically come on over minutes to hours.[1]

Common causes include insect bites and stings, foods, and medications.[1] Other causes include latex exposure and exercise.[1] Additionally, cases may happen without an obvious reason.[1] The mechanism involves the release of mediators from certain types of white blood cells triggered by either immunologic or non-immunologic mechanisms.[6] Diagnosis is based on the presenting symptoms and signs after exposure to a potential allergen.[1]

The primary treatment of anaphylaxis is epinephrineinjection into a muscle, intravenous fluids, and positioning the person flat.[1][7] Additional doses of epinephrine may be required.[1] Other measures, such as antihistamines and steroids, are complementary.[1] Carrying an epinephrine autoinjector and identification regarding the condition is recommended in people with a history of anaphylaxis.[1]

Worldwide, 0.05–2% of the population is estimated to experience anaphylaxis at some point in life.[3] Rates appear to be increasing.[3] It occurs most often in young people and females.[7][8] Of people who go to a hospital with anaphylaxis in the United States about 99.7% survive.[9] The term comes from the Ancient Greek: ἀνά, romanized: ana, lit. 'against', and the Ancient Greek: φύλαξις, romanized: phylaxis, lit. 'protection'.[10]


Who’s affected?

Most food allergies affect younger children under the age of 3.

Most children who own food allergies to milk, eggs, soya and wheat in early life will grow out of it by the time they start school.

Peanut and tree nut allergies are generally more endless lasting.

Food allergies that develop during adulthood, or persist into adulthood, are likely to be lifelong allergies.

For reasons that are unclear, rates of food allergies own risen sharply in the final 20 years.

However, deaths from anaphylaxis-related food reactions are now rare.


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