Food allergies can give rise to a wide variety of symptoms that affect different parts of the body, 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, that costs the parent immediately contact the pediatrician, bearing in mind that:
- Food allergies and intolerances are not the same thing
For food allergy is meant 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 characterized by itching, rashes and, in the most serious cases, a sensation of air hunger and even anaphylactic shock.
Food intolerances, on the other hand, give rise mostly to malaise and above all to 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 substance “incriminated”. An example is lactose intolerance, due to the lack of lactase, the enzyme necessary to assimilate it.
- Gluten: allergy, intolerance or celiac disease ?
Gluten is a protein contained in wheat and in some varieties of cereals such as spelled, spelled, 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 the (reversible) flattening of the intestinal villi, resulting in malabsorption and in some cases stunting.
In addition to celiac disease, there is also an allergy to wheat , a reaction of the immune system towards one or more proteins present in cereals, including gluten, which causes typically allergic symptoms (such as rhinitis, asthma, conjunctivitis , etc.) and the non-celiac gluten sensitivity , still under investigation, in which the introduction of gluten causes certain gastrointestinal symptoms (abdominal pain, vomiting, diarrhea, which can also be associated with headache and fatigue) that do not depend on damage to the ‘intestine, as in celiac disease, and which tend to regress spontaneously by eliminating gluten from the diet.
- Correct diagnosis is always essential
Never trust gross assumptions or invalid tests! The diagnosis of allergy must be made by the pediatrician who, in addition to collecting the history, will prescribe the necessary investigations, including skin tests (the prick test) and blood tests for the determination of antibodies, in particular total IgE (RIST) or specifications (RAST). Another important tool is the triggering test which consists in having the child – if necessary in a protected environment – assume the suspect food to observe any reactions.
- Atopic dermatitis, food allergies and cross reactivity
Allergies are often unpredictable manifestations and can hold numerous surprises, from the appearance in adulthood, even in people who had never suffered from it, to sensitization to foods that a child with atopic dermatitis has not yet taken, such as for example peanuts 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 watermelon or banana; or in those allergic to birch, apple and peach could also trigger an allergic reaction.
- I am not a life sentence
Once the diagnosis has been made, the parents ask if their child can no longer take the responsible food (for example milk or egg) for life. In fact most of the allergies that occur early tend to fade towards the first year of life.
Just in an attempt to induce tolerance, that is to make the allergic mechanism go out, the pediatrician often suggests that they try to reintroduce the component after having eliminated it for 2-3 weeks