Food allergies in children: 5 things to know

There are over 170 foods that can cause allergies, affecting an average of between 5 and 8 children out of 100 every year in Italy.

As in the case of respiratory or contact allergies, food allergies can also give rise to a wide variety of symptoms that affect different body districts, from the respiratory tract (rhinitis, cough, sneezing, asthma) to the skin (dermatitis, redness, erythema) up to the digestive system (diarrhea, abdominal pain).

If it is a child, even a small one, who pays the price, it is good that the parent immediately contacts the pediatrician, bearing in mind that:

1. Food allergies and intolerances are not the same thing

Food allergy is an abnormal response of the immune system, triggered by even minimal contact with an allergen (for example milk proteins) contained in a normally harmless food and characterized by itching, rashes and, in severe cases, a feeling of air hunger and even anaphylactic shock.

Food intolerances, on the other hand, mostly give rise to malaise and especially digestive disorders (diarrhea, abdominal bloating), are less serious than allergies and are dose-dependent, ie their manifestations are proportional to the extent of exposure to the “offending” substance. An example is lactose intolerance, due to the lack of lactase, the enzyme necessary to assimilate it.

2.Il gluten: allergy, intolerance or… celiac disease?

Gluten is a protein contained in wheat and in some varieties of cereals such as spelt, spelt, triticale, barley and rye. After the previous clarification, a clarification is inevitable and necessary: the expression gluten intolerance is improper and should not be used as a synonym for celiac disease, which is an autoimmune disease. The introduction of gluten causes flattening (reversible) of the intestinal villi, which results in malabsorption and in some cases stunting.

In addition to celiac disease, there are also wheat allergy, a reaction of the immune system to one or more proteins present in cereals, including gluten, which causes typically allergic symptoms (such as rhinitis, asthma, conjunctivitis, etc.) and sensitivity to non-celiac gluten, still being studied, in which the introduction of gluten causes some gastrointestinal symptoms (abdominal pain, vomiting, diarrhea, which can also be associated with headaches and fatigue) that do not depend on damage to the intestine, as in celiac disease, and that tend to regress spontaneously by eliminating gluten from the diet.

3.A correct diagnosis is always essential

Never trust gross assumptions or unvalidated tests! The diagnosis of allergy should be made by the pediatrician who, in addition to collecting the anamnesis, will prescribe the necessary investigations, including skin tests (the prick test) and blood tests for the dosage of antibodies, in particular total IgE (RIST) or specific (RAST). Another important tool is the trigger test which consists in making the child take – if necessary in a protected environment – the suspicious food to observe any reactions.

4.Atopic dermatitis, food allergies and cross-reactivity

Allergies are often unpredictable manifestations and can reserve numerous surprises, from the appearance in adulthood, even in people who had never suffered from them, to sensitization to foods that a child with atopic dermatitis has not yet taken, such as peanuts even before weaning.

In the case of this particular dermopathy, the reason lies in the fact that the defect of the skin barrier allows some components, including peanut powder, to penetrate and stimulate the immune system in this way.

There is also the so-called cross-reactivity, due to the chemical similarity between different allergens contained in some foods, but not only: the child allergic to melon, for example, can also be allergic to watermelon or banana; or in the one allergic to birch, apple and peach could also trigger an allergic reaction.

5.They are not a life sentence

Once diagnosed, parents ask if their child will no longer be able to take the responsible food (e.g. milk or egg) for life. In fact, most allergies that occur early tend to fade around the first year of life.

Precisely in an attempt to induce tolerance, that is, to turn off the allergic mechanism, the pediatrician often suggests them to try to reintroduce the component after eliminating it for 2-3 weeks.