What causes peanut allergy reaction

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. peanuts
  3. fish
  4. eggs
  5. shellfish
  6. milk
  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.


Anaphylaxis

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

Call 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.


Peanut allergy

Your kid has a higher risk of developing a peanut allergy if they already own a known allergy (such as eczema or a diagnosed food allergy), or there’s a history of allergy in their immediate family (such as asthma, eczema or hay fever).

There is evidence that having peanuts regularly before 12 months can reduce the risk of developing peanut allergy.

If your kid already has an egg allergy, another food allergy or severe eczema, talk to your doctor before you give peanuts or food containing peanuts to your kid for the first time.

If you would love to eat peanuts or foods containing peanuts (such as peanut butter) while breastfeeding, you can do so unless you’re allergic to them or your health professional advises you not to.

Avoid giving your kid peanuts and foods containing peanuts before the age of 6 months.

Foods containing peanuts include peanut butter, peanut (groundnut) oil and some snacks. Little children are at a higher risk of choking on little objects, so avoid giving whole peanuts or nuts to children under age 5-years-old.

Read food labels carefully and avoid foods if you’re not certain whether they contain peanuts.


Introducing allergens

It’s recommended that when your baby is ready, at around 6 months (but not before 4 months), introduce a variety of solid foods, starting with iron-rich foods, while continuing breastfeeding. Hydrolysed (partially and extensively) baby formula is not recommended for the prevention of allergies.

When you start introducing solids (weaning), introduce the foods that commonly cause allergies one at a time so that you can spot any reactions.

Don’t delay introducing a food just because it’s considered a common allergen. These foods include: milk, eggs, wheat, nuts, seeds, fish and shellfish. However, don’t introduce any of these foods before 6 months.

There is evidence that infants should be given allergenic solid foods including peanut butter, cooked egg and dairy and wheat products in the first year of life. This includes infants at high risk of allergy.

Don’t be tempted to experiment by cutting out a major food, such as milk, as this could lead to your kid not getting the nutrients they need.

Talk to your doctor, who may refer you to a registered dietitian.


If your kid has symptoms after eating certain foods, he or she may own a food allergy.

A food allergy occurs when the body’s immune system sees a certain food as harmful and reacts by causing symptoms. This is an allergic reaction. Foods that cause allergic reactions are allergens.

IgE Mediated Food Allergies

The IgE mediated food allergies most common in infants and children are eggs, milk, peanuts, tree nuts, soy and wheat. The allergic reaction can involve the skin, mouth, eyes, lungs, heart, gut and brain.

What causes peanut allergy reaction

Some of the symptoms can include:

  1. Stomach pain, vomiting, diarrhea
  2. Shortness of breath, trouble breathing, wheezing
  3. Feeling love something terrible is about to happen
  4. Swelling of the lips, tongue or throat
  5. Immunoglobulin E (IgE) mediated. Symptoms result from the body’s immune system making antibodies called Immunoglobulin E (IgE) antibodies. These IgE antibodies react with a certain food.
  6. Skin rash, itching, hives
  7. Non-IgE mediated. Other parts of the body’s immune system react to a certain food. This reaction causes symptoms, but does not involve an IgE antibody.

    Someone can own both IgE mediated and non-IgE mediated food allergies.

Sometimes allergy symptoms are mild. Other times they can be severe. Take every allergic symptoms seriously. Mild and severe symptoms can lead to a serious allergic reaction called anaphylaxis (anna-fih-LACK-sis). This reaction generally involves more than one part of the body and can get worse quick. Anaphylaxis must be treated correct away to provide the best chance for improvement and prevent serious, potentially life-threatening complications.

Treat anaphylaxis with epinephrine.

This medicine is safe and comes in an easy-to-use device called an auto-injector. You can’t rely on antihistamines to treat anaphylaxis. The symptoms of an anaphylactic reaction happen shortly after contact with an allergen. In some individuals, there may be a delay of two to three hours before symptoms first appear.

Cross-Reactivity and Oral Allergy Syndrome

Having an IgE mediated allergy to one food can mean your kid is allergic to similar foods. For example, if your kid is allergic to shrimp, he or she may be allergic to other types of shellfish, such as crab or crayfish.

Or if your kid is allergic to cow’s milk, he or she may also be allergic to goat’s and sheep’s milk. The reaction between diverse foods is called cross-reactivity. This happens when proteins in one food are similar to the proteins in another food.

Cross-reactivity also can happen between latex and certain foods. For example, a kid who has an allergy to latex may also own an allergy to bananas, avocados, kiwis or chestnuts.

Some people who own allergies to pollens, such as ragweed and grasses, may also be allergic to some foods.

Proteins in the pollens are love the proteins in some fruits and vegetables. So, if your kid is allergic to ragweed, he or she may own an allergic reaction to melons and bananas. That’s because the protein in ragweed looks love the proteins in melons and bananas. This condition is oral allergy syndrome.

Symptoms of an oral allergy syndrome include an itchy mouth, throat or tongue.

Symptoms can be more severe and may include hives, shortness of breath and vomiting. Reactions generally happen only when someone eats raw food. In rare cases, reactions can be life-threatening and need epinephrine.

Two Categories of Food Allergies

  • a raised itchy red rash (urticaria, or «hives»)
  • Non-IgE mediated. Other parts of the body’s immune system react to a certain food. This reaction causes symptoms, but does not involve an IgE antibody. Someone can own both IgE mediated and non-IgE mediated food allergies.
  • swelling of the face, around the eyes, lips, tongue and roof of the mouth (angioedema)
  • an itchy sensation inside the mouth, throat or ears
  • Immunoglobulin E (IgE) mediated.

    Symptoms result from the body’s immune system making antibodies called Immunoglobulin E (IgE) antibodies. These IgE antibodies react with a certain food.

  • vomiting

Non-IgE Mediated Food Allergies

Most symptoms of non-IgE mediated food allergies involve the digestive tract. Symptoms may be vomiting and diarrhea. The symptoms can take longer to develop and may final longer than IgE mediated allergy symptoms. Sometimes, a reaction to a food allergen occurs up 3 days after eating the food allergen.

When an allergic reaction occurs with this type of allergy, epinephrine is generally not needed.

In general, the best way to treat these allergies is to stay away from the food that causes the reaction. Under are examples of conditions related to non-IgE mediated food allergies.

Not every children who react to a certain food own an allergy. They may own food intolerance. Examples are lactose intolerance, gluten intolerance, sulfite sensitivity or dye sensitivity. Staying away from these foods is the best way to avoid a reaction.

Your child’s doctor may propose other steps to prevent a reaction. If your kid has any food allergy symptoms, see your child’s doctor or allergist. Only a doctor can properly diagnose whether your kid has an IgE- or non-IgE food allergy. Both can be present in some children.

Eosinophilic Esophagitis (EoE)

Eosinophilic (ee-uh-sin-uh-fil-ik) esophagitis is an inflamed esophagus.

The esophagus is a tube from the throat to the stomach. An allergy to a food can cause this condition.

With EoE, swallowing food can be hard and painful. Symptoms in infants and toddlers are irritability, problems with eating and poor weight acquire. Older children may own reflux, vomiting, stomach pain, chest pain and a feeling love food is “stuck” in their throat. The symptoms can happen days or even weeks after eating a food allergen.

EoE is treated by special diets that remove the foods that are causing the condition.

Medication may also be used to reduce inflammation.

Food Protein-Induced Enterocolitis Syndrome (FPIES)

FPIES is another type of food allergy. It most often affects young infants. Symptoms generally don’t appear for two or more hours. Symptoms include vomiting, which starts about 2 hours or later after eating the food causing the condition. This condition can also cause diarrhea and failure to acquire weight or height.

Once the baby stops eating the food causing the allergy, the symptoms go away. Rarely, severe vomiting and diarrhea can happen which can lead to dehydration and even shock. Shock occurs when the body is not getting enough blood flow. Emergency treatment for severe symptoms must happen correct away at a hospital. The foods most likely to cause a reaction are dairy, soy, rice, oat, barley, green beans, peas, sweet potatoes, squash and poultry.

Allergic Proctocolitis

Allergic proctocolitis is an allergy to formula or breast milk.

This condition inflames the lower part of the intestine. It affects infants in their first year of life and generally ends by age 1 year.

The symptoms include blood-streaked, watery and mucus-filled stools. Infants may also develop green stools, diarrhea, vomiting, anemia (low blood count) and fussiness. When properly diagnosed, symptoms resolve once the offending food(s) are removed from the diet.

Medical review December

A food allergy is when the body’s immune system reacts unusually to specific foods.

Although allergic reactions are often mild, they can be extremely serious.

Symptoms of a food allergy can affect diverse areas of the body at the same time. Some common symptoms include:

  1. a raised itchy red rash (urticaria, or «hives»)
  2. an itchy sensation inside the mouth, throat or ears
  3. swelling of the face, around the eyes, lips, tongue and roof of the mouth (angioedema)
  4. vomiting

Read more about the symptoms of food allergies.

Non-IgE Mediated Food Allergies

Most symptoms of non-IgE mediated food allergies involve the digestive tract.

Symptoms may be vomiting and diarrhea. The symptoms can take longer to develop and may final longer than IgE mediated allergy symptoms. Sometimes, a reaction to a food allergen occurs up 3 days after eating the food allergen.

When an allergic reaction occurs with this type of allergy, epinephrine is generally not needed. In general, the best way to treat these allergies is to stay away from the food that causes the reaction. Under are examples of conditions related to non-IgE mediated food allergies.

Not every children who react to a certain food own an allergy. They may own food intolerance.

Examples are lactose intolerance, gluten intolerance, sulfite sensitivity or dye sensitivity. Staying away from these foods is the best way to avoid a reaction. Your child’s doctor may propose other steps to prevent a reaction. If your kid has any food allergy symptoms, see your child’s doctor or allergist.

What causes peanut allergy reaction

Only a doctor can properly diagnose whether your kid has an IgE- or non-IgE food allergy. Both can be present in some children.

Eosinophilic Esophagitis (EoE)

Eosinophilic (ee-uh-sin-uh-fil-ik) esophagitis is an inflamed esophagus. The esophagus is a tube from the throat to the stomach. An allergy to a food can cause this condition.

With EoE, swallowing food can be hard and painful. Symptoms in infants and toddlers are irritability, problems with eating and poor weight acquire.

What causes peanut allergy reaction

Older children may own reflux, vomiting, stomach pain, chest pain and a feeling love food is “stuck” in their throat. The symptoms can happen days or even weeks after eating a food allergen.

EoE is treated by special diets that remove the foods that are causing the condition. Medication may also be used to reduce inflammation.

Food Protein-Induced Enterocolitis Syndrome (FPIES)

FPIES is another type of food allergy. It most often affects young infants. Symptoms generally don’t appear for two or more hours.

What causes peanut allergy reaction

Symptoms include vomiting, which starts about 2 hours or later after eating the food causing the condition. This condition can also cause diarrhea and failure to acquire weight or height. Once the baby stops eating the food causing the allergy, the symptoms go away. Rarely, severe vomiting and diarrhea can happen which can lead to dehydration and even shock.

What causes peanut allergy reaction

Shock occurs when the body is not getting enough blood flow. Emergency treatment for severe symptoms must happen correct away at a hospital. The foods most likely to cause a reaction are dairy, soy, rice, oat, barley, green beans, peas, sweet potatoes, squash and poultry.

Allergic Proctocolitis

Allergic proctocolitis is an allergy to formula or breast milk. This condition inflames the lower part of the intestine. It affects infants in their first year of life and generally ends by age 1 year.

The symptoms include blood-streaked, watery and mucus-filled stools.

Infants may also develop green stools, diarrhea, vomiting, anemia (low blood count) and fussiness. When properly diagnosed, symptoms resolve once the offending food(s) are removed from the diet.

Medical review December

A food allergy is when the body’s immune system reacts unusually to specific foods. Although allergic reactions are often mild, they can be extremely serious.

Symptoms of a food allergy can affect diverse areas of the body at the same time. Some common symptoms include:

  1. a raised itchy red rash (urticaria, or «hives»)
  2. an itchy sensation inside the mouth, throat or ears
  3. swelling of the face, around the eyes, lips, tongue and roof of the mouth (angioedema)
  4. vomiting

Read more about the symptoms of food allergies.


How will I know if my kid has a food allergy?

Signs and symptoms of an allergic reaction can include:

  1. itchy throat and tongue
  2. wheezing and shortness of breath
  3. swollen lips and throat
  4. rash or itchy skin
  5. cough
  6. vomiting
  7. diarrhoea
  8. runny or blocked nose
  9. sore, red and itchy eyes

The Australasian Society of Clinical Immunology and Allergy (ASCIA) recommends talking to your doctor or specialist about the specific testing available for a food allergy.

ASCIA also recommends that you speak to your doctor or specialist about the benefits and safety of allergen immunotherapy before commencing any treatment for a food allergy.

For further information about ASCIA’s recommendations, visit the Choosing Wisely Australia website.

In a few cases, foods can cause a extremely severe reaction (anaphylaxis) that can be life-threatening. If you ponder your kid is having an allergic reaction to a food, seek medical advice urgently as symptoms can worsen rapidly.

If breathing is affected, call triple zero () and enquire for an ambulance.

Sources:

NHS Choices (UK)(Your baby’s first solid foods), Choosing Wisely Australia(Choosing Wisely recommendations), NHS Choices (UK)(Food allergies in babies), Australasian Society of Clinical Immunology and Allergy(Infant feeding and allergy prevention)

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: June

Back To Top

What is a Food Allergy?

There Are Diverse Types of Allergic Reactions to Foods


Food additives

Food contains additives for a variety of reasons, such as to preserve it, to assist make it safe to eat for longer and to give colour or texture.

All food additives go through rigorous assessments for safety before they can be used. Food labelling must clearly show additives in the list of ingredients, including their name or number and their function, such as ‘colouring’ or ‘preservative’.

A few people own adverse reactions to some food additives, but reactions to ordinary foods, such as milk or soy, are much more common.


RELATED VIDEO: