Peanut allergy explained in details

Peanuts are available across the world and it is a cheap food content with proteins and oil in it. Many people in the world have peanuts allergy.

What is peanut allergy?

Peanut allergy is a type of food allergy. We have discussed food allergies in earlier posts, now we will discuss peanut allergy here.

As everyone knows peanuts are available across the world and we almost daily use it in each dish. It is a source of proteins and oils. Even the peanuts are used as animal foods.

In some people peanuts may induce allergy. When they consume the food containing peanuts they may show allergic symptoms.

These allergic symptoms may range from mild to severe. 

What are the symptoms of the peanut allergy?

The manifestations of the food allergy can be mild to moderate and have a variety of manifestations. The manifestations may depend upon the involving organ system.

So let us see how food allergy can manifest in your children or even in adults:

Cutaneous manifestations

Early manifestations of peanuts allergy include symptoms of skin like pruritus that is itching of skin and redness and insect bite like macules on skin. There may be marks of excoriation if the patient has tried to scratch the area where symptoms come. Sometimes there may be an appearance of measles like rash on the skin. If it occurs repeatedly, the dry and hard scales may be developed on the skin.

Eye manifestations

Peanut allergy may cause itching of eyes. The conjunctiva of the eyes may appear red. Eyes may have watery discharge or tears. The pupils and area around the eyes may swell in this condition. These manifestations may occur within a few hours of food intake.

Upper respiratory tract

Peanuts allergy may cause upper respiratory tract infections. They are stuffy or congested nose, running nose, sneezing, and itching sensations in nose and throat with throat pain, changed voice like hoarseness and dry cough. Extreme conditions like swelling of larynx which may block the windpipe that may be life threatening.

Lower respiratory tract

Peanuts allergy may cause lower respiratory tract symptoms like difficulty in breathing and wheezing that whistle like the sound a person breaths. Cough and feeling of tightness in chest. You may see skin between the ribs sagging in the chest when a person breaths. These symptoms are all similar to asthma. They can appear within a few minutes to hours after having food.

Oral symptoms

These symptoms may occur because of food allergy and they appear around or inside the mouth. They include itching and swelling of lips and palate, tongue. It may cause difficulty in eating breathing if the respiratory tract also is involved.

Other digestive tract manifestations

Feeling of nausea, abdominal pain and vomiting, diarrhea. In some children it may cause blood in stool which may be frightening for the parents. In some children there may be irritability and refusal to food and also after some days may cause loss of weight or failure to gain weight.

Cardiological (heart) manifestations

In some children food allergy may cause increased or decreased heart rate with decreased blood pressure. This decreased blood pressure may cause fainting and dizziness. This condition is called anaphylaxis. If not managed immediately may cause death.

What is the course of peanut allergy?

First time manifestations of the peanuts allergy usually appear at age 1-2 years of age. These children may be allergic to other legumes and lentils and peas and nuts.

Usually other allergies resolve when the child grows but peanut allergy is one of the food allergies that can continue for life. 20 percent of children who have peanut allergy may continue to be so when they grow older.

How to prevent peanut allergy?

Like any other food allergy peanut allergy can be prevented by some measures that prevent food allergies.

Following are the simple ways which help to reduce the incidences of food allergies in children.


If you are allergic to something and that allergy can come in severe form you should carry an Epipen and Id card stating you are allergic to something.

If you get a severe life threatening allergic reaction that can kill you in minutes at such moments Epipen can save you.

Epipen contains injection epinephrine and it is an autoinjector anyone can inject it easily to a person suffering from allergy.

Exclusive breastfeeding

Breastfeeding is the best food  for babies. We have already explained the benefits of breastfeeding in an earlier post. Exclusive breastfeeding for the first 6 months of the life protects infants and children from developing food allergies in future.

Complementary food

Complementary food should be started to infants at 6 months of age. Starting complementary food at 6 months of age after giving exclusive breastfeeding for the first 6 months of life reduces the chances of food allergy.

Introduce single food at a time

In complementary feeding infants should be introduced to single food at the time. Initially low risk food is introduced. Like if you are introducing rice, give the food made up of only rice for 4 days then introduce other pulses one by one.

High risk foods

Introduce potentially highly allergenic foods (fish, eggs, peanut products, milk, wheat) soon after the lower-risk foods (no need to avoid or delay)

Don’t avoid allergenic foods during pregnancy or nursing.

Soy-based formula

There is a myth that soy based formulas prevent allergic disease which is not true. Soy-based formulas do not prevent allergic disease.

How to diagnose peanut allergy?

Knowledge of the symptoms helps to diagnose the food allergy. A thorough history is needed to diagnose this condition. 

The parent who daily feeds the child should accompany the child to the doctor to give the detailed history about diet and the symptoms.

Additionally you should carry the relevant medical history file if any to see the previous record of treatment and growth of the child.

History and physical examination

The goal of detailed history are to establish facts about:


The history can suggest the food which can provoke the allergic reaction and how much quantity of food was ingested before the symptoms.


The history about diet also helps to find out the interval between ingestion of the provoking food and appearance of the symptoms.


The history taking helps to find out the types of symptoms and their severity.


Whether there were similar episodes of symptoms with similar food in the past. How frequently it has occurred in the past.

Lab tests

Lab tests can be used to identify provoking agents which can induce the symptoms in the patients. These lab tests mainly detect the IgE antibody mediated allergic reactions to the food.

Prick test

Prick test is used to detect the allergy to specific food if known in history as a provoking agent.

The produce from the fresh fruits are useful for this test as readymade preparation may alter the antigens from the fruits.

In this test the fruit product is injected in a small amount on skin and the response is observed for a few minutes.

Negative test virtually excludes the possibility of the reactivity or allergy to that food.

Positive test does not indicate that the patient has a confirmed allergy to that food. The patients who test positive on tests may not be allergic to food when ingesting that food.

So rather than confirming, the prick test is for excluding the allergy to the food.

Further confirmation with specific IgE antibody tests is useful. Quantitative IgE levels are used to detect the allergy.

IgE levels

  • ≥14 kUA/L for peanuts are associated with a >95% likelihood of clinical reactivity to these foods in children with suspected reactivity.

Food elimination and challenge test

Above tests are not helpful for the cell mediated food allergies and other reactions. So eliminating a suspected group of food for a period and then introducing that food to see whether symptoms reappear is the only practical test to assess whether the patient is allergic to a food.

These tests are performed by allergy specialists who have skill to manage anaphylaxis. Before a challenge test the food is stopped for 14 days to 8 weeks depending on the type of allergic reaction suspected and then it is introduced under observation.

What is treatment for peanut allergy?

Identifying and then eliminating the food to which a child is allergic is the only approach to treat the peanut allergy.

Acute symptoms of peanut allergy

Acute symptoms that occur after the consumption of peanuts are treated based on symptoms.


If the symptoms are severe like anaphylaxis, the patient immediately needs epinephrine injection. Epinephrine is the only drug that reverses the allergy. 

Epinephrine is life saving medicine in case of anaphylaxis and it is given by injection. Epinephrine auto injector Epipen can be used for this purpose.


Antihistamines are antiallergic drugs. For mild allergic symptoms they can be given orally or by injection for severe symptoms. They reduce the symptoms of allergy in a few minutes.


Steroids are also antiallergic drugs. They are useful in allergies. In emergency doctors give that by injection or in other cases they give it orally.

Gastrointestinal symptoms

Gastro-intestinal symptoms are managed symptomatically. For loose motions rehydrating therapy like oral rehydration solution (ORS0 can be used.

For vomiting medicine like ondansetron can useful. It can be taken orally or by injection.

Elimination of the food

Always read the contents of the food whether it contains peanuts. Avoid food containing peanuts if you are allergic to peanuts.


This is a type of immunotherapy and can be useful to reduce the allergy to specific antigen by allergist.

Moreover most of the children with food allergy outgrow the condition in a few years so the child should be evaluated periodically whether the eliminated food can be introduced.

<span class="has-inline-color has-luminous-vivid-orange-color">Dr Yatin Bhole MBBS DCh DNB</span>
Dr Yatin Bhole MBBS DCh DNB

This article was written by Dr Yatin Bhole who is practicing Pediatrician at Bhole Children Clinic, Ravet. This post is for general information and before applying it on yourself, you should meet your doctor or meet us in person.

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