Allergic reactions to food

An allergic reaction to a food is an abnormal response of the body to exposure to a food and can be of two types

Hypersensitivity reactions

They depend on individual susceptibility and only affect a part of the population and can be:

• Food allergy: reaction of immunological origin demonstrated. There are two types:
  • IgE dependent: these are reactions that occur in atopic children and that present IgE antibodies with positive allergy tests.
  • Non-IgE dependent: immunological reactions other than IgE
• Food intolerance or non-allergic hypersensitivity: non-toxic food reaction in which an immune mechanism is not demonstrated. They are divided into:
  • Enzyme food intolerance: produced by the absence or decrease of a basic enzyme in digestion (for example, lactase deficiency)
  • Pharmacological food intolerance: due to the effect of food-borne drugs that give rise to urticarial reactions (for example histamine)

Toxic reactions

Due to the action of toxic substances that contaminate food or are naturally present. They can affect anyone.

Why do we react to certain foods?

Food allergy affects 3% of children, but in infants it can reach up to 6%.

• Children with atopic dermatitis are more likely to have a food allergy.
• The foods most frequently implicated depend on the Feeding Habits and in our environment they are: egg, cow's milk, fish, legumes and fruit-nuts.
• The cow's milk allergy starts in the first months of life, sometimes even after the first intake of adapted cow's milk formula and generally within the first week of its introduction into the diet.
• The egg allergy manifests itself coinciding with his introduction on 12 months of life. Good tolerance to yolk and the appearance of symptoms with whole egg is common.
• The fish allergy It also begins in relation to its introduction and in most cases it appears in the First 2 years of age.

Common symptoms

It can give various allergy symptoms depending on the immune cause:

IgE-mediated food allergy

The child can present a wide range of symptoms from mild to life threatening (in the case of anaphylaxis). The allergic reaction is usually caused by food intake but it can also be caused by skin contact or by inhaling cooking products or vapors. The skin contact It can also be through kisses, caresses by the person who cooks or handles the food. Clinical manifestations begin between a few minutes to an hour from the exhibition to food and its most frequent symptoms is cutaneous (urticaria, angioedema) followed by gastrointestinal symptoms (vomiting, diarrhea) and respiratory symptoms (rhinoconjunctivitis, bronchospasm or asthma).

Food allergy is the leading cause in children of anaphylaxis: Symptoms start within seconds to 30 minutes after exposure to food, usually with the appearance of symptoms on the skin of urticaria-angioedema, (although sometimes it can be initiated by an itchy sensation of itching in the tongue, narrowing of the throat, abdominal pain and vomiting) that can be followed by digestive symptoms (vomiting, abdominal pain, diarrhea) and in severe symptoms, respiratory and / or cardiocirculatory symptoms, which can endanger the life of the patient due to severe bronchospasm, glottis edema or anaphylactic shock.

Non-IgE-mediated food allergy

They are a series of diseases that mainly affect the digestive system. The so-called enteropathies, enterocolitis and proctocolitis caused by cow's milk proteins during the first 6 months of life, are the most frequent. They are usually paintings that resolve on their own without treatment with the maturity of the child. Eggs and fish, among other foods, can also cause it. The most frequent symptoms are bleeding from the stool accompanied by a great general condition of the child. Another type of non-IgE-mediated food reaction would be celiac disease (gluten intolerance) but it persists throughout life.

Diagnosis

When an adverse relationship to a food is suspected, it must be removed from the child's diet and studied by the allergist. The diagnostic process consists of skin tests on the skin (prick test), analytical tests and, where indicated, controlled oral provocation.

Treatment

Currently the recommended treatment for food allergy is based on:

• Elimination of the responsible food and other foods with known cross-reaction until definitive diagnosis.
• Education of the patient and his family, about the elimination diet and possible hidden sources to avoid accidental ingestion.
• Treatment of symptoms before accidental ingestion.

Over time many patients reach tolerance, but this does not occur in all cases.