Rash From Food Allergy

This guide is aimed at the rash from food allergy with various symptoms such as diarrhea, vomiting, asthma and itching for eating different foods.

1) What is allergy?

Allergy is an alteration of the immune defense mechanisms of the organism. The allergic reacts in a different way to non-allergic, to various substances with which we are usually in contact. (food, medicines, dust, pollens, etc.)

2) What does it mean to be allergic to a food?

It means reacting abnormally to a specific food, which in non-allergic people, does not produce any kind of reaction.

In general, the food is not what causes the allergic reaction, but its proteins and the way in which the food is prepared will not modify the possibility of causing an allergy.

For example:
-I’m allergic to the egg

Therefore I can not eat it fried, or hard, or mixed with other foods (eg: in cakes)

Therefore I can eat it fried, hard, in other foods (cakes, milanesas, etc.)

There is no allergy to fried or so-called liver allergy, what exists is food allergy, regardless of the way it is prepared.

3) Are all the reactions produced by the food allergic?

No, not all are allergic reactions. It can happen that a person does not tolerate a food because some substance has been added to it to have more color, or to be preserved for a longer time.

4) Who are most allergic to food?

In general, we can all be allergic to some food, but it is more frequent in children. The inheritance influences, the place where one lives, and what type of food one is accustomed to eat.

5) What are the foods that most frequently cause an allergic reaction?

It is difficult to list the foods that cause allergic reactions, because it depends a lot on each person; but there are foods that cause allergy more frequently, for example:

  • Milk
  • Fish and seafood
  • Tomato
  • Nuts (walnuts, almonds, hazelnuts)
  • Citrus
  • Cereals

You should also take into account condiments, dyes and preservatives, which are added to food (packaged, sausage or natural) or drinks, to have better appearance, color or preservation.

6) How does food allergy manifest itself?

Rash From Food AllergyFood allergy can manifest itself in different ways and in different parts of the body. It is characteristic that when you eat the food that causes allergy (allergenic food) the symptoms appear (for example: asthma, hives) and if you stop eating that food the symptoms disappear.

The clinical manifestations vary from a mild reaction (for example a few hives) to very serious and life-threatening.

The skin is often affected: where red, inflamed, itchy bumps appear and can occupy small areas throughout the body.

In young children, food often causes or worsens allergic eczema or atopic dermatitis, which is an allergic inflammation of the skin that appears on the arms, legs, neck, behind the knees or on the face.


Rhinitis (itchy nasal discomfort, sneezing, discharge) and asthma (bronchial disease where wheezing and wheezing appear in the chest) can be manifestations of food allergy.


Your lips, tongue, and throat may sting or swell after you have eaten the allergenic food. These reactions can be transient or be the first symptoms of a more serious reaction. Other related symptoms are: nausea, diarrhea, abdominal pain, cramps, vomiting.

7) What happens in a severe allergic reaction?

In general, severe reactions appear between 5 and 30 minutes after ingesting the allergenic food. The first symptoms are usually: redness, itching, swelling and heat in the skin; followed or accompanied by difficulty breathing, vomiting, abdominal pain, diarrhea, anxiety, loss of consciousness, fainting. It is very important that if these manifestations occur, quickly consult the nearest specialist or Health Center.

8) Can preservatives and colorants in packaged foods cause allergy?

Many times, these aggregates (which are chemical substances), do not cause an allergic reaction, but a reaction of “intolerance”, that is, the patient is not allergic to that food; but it does not tolerate it. Dyes and preservatives are found in packaged foods (eg, gelatin, potato chips, ice cream, candy) in sausages (cold meats, cheeses, sausages) in beverages (artificial juices, some soft drinks, etc.) and in certain medicines. The manifestations are the same as that of an allergic reaction.

9) Diagnosis:

It must be based fundamentally on:

  • The specific questions that the specialist asks the patient (Clinical History): The Clinical History must be complete, taking into account all the foods and beverages consumed in the days prior to the consultation. It is suggested that the patient make a few days, a report written (daily) of the food you eat, so you can relate them to the development of symptoms.
  • Physical exam.
  • Elimination diet: It consists in eliminating suspect foods, approximately during 15 days, to observe if in this way the allergic symptoms of the patient disappear. if the suspected foods are more than one, each must be tested separately, leaving between them a period of not less than 3 days.
  • RAST: it is an analysis that is made in the blood of the patient, to investigate if it presents IgE antibodies specific to certain foods.

10) Treatments

Not eating the ALLERGENIC FOOD is the ONLY and the most EFFECTIVE of the treatments.

Patients should be warned that the food that causes allergy may be hidden in other foods or food preparations; so before eating any food or preparation, you must ensure all the ingredients that make it up. The same happens if you buy packaged foods, (for example, mayonnaise) or precooked foods (you should always read the labels on their composition).

Treating food allergy with drugs can only help when the symptoms do not disappear, or when the allergenic food can not be excluded from the diet. Patients who have had severe reactions should be advised, always carry emergency medication, to be able to use it at any time and place, as well as an identification (for example a medal), with the name of the food to which they are allergic .

11) Can food allergy be treated with vaccines?

No, the ONLY possible treatment is NOT to ingest the allergenic food.

12) Is the diet for life?

Not always, usually, especially in children, an early and correct diet, makes the patient can, over time, incorporate the allergenic food.

By: Drs. Marcela Soria and José L. di Paola