Following exposure to foreign substances, the body can develop a sensitization reaction called an allergy:
an abnormal response of the immune system , which produces large quantities of antibodies, immunoglobin E (IgE). There are numerous potentially allergenic substances: first of all
pollens (cause of almost half of allergies),
foods and medicines, normally harmless for most people. Constitutional factors and hereditary predisposition are decisive for the occurrence of allergies, which largely affect children, the most sensitive and at risk category. The first thing to do is therefore to identify
the offending allergen early by using the appropriate tests.
ALLERGIC MANIFESTATIONS
The allergen can enter the body by bronchial, digestive or contact routes, causing inflammation and pathologies (perennial or seasonal) affecting various organs.
■ RHINITIS : inflammation of the nasal mucosa accompanied by sneezing, itching, stuffy and runny nose, while the child continues to rub his nose from bottom to top (the so-called 'allergic greeting'). Causes: dust mites, pollen and some moulds.
■ CONJUNCTIVITIS : inflammation of the eye often associated with rhinitis (oculorhinitis). Symptoms: red watery eye, 'grit in the eye' sensation, intense itching, sensitivity to light.
■ ASMA : chronic inflammatory disease of the bronchi, which manifests itself with shortness of breath and wheezing; it can also start with a dry cough, but as it gets worse, the bronchial spasm becomes evident. Diagnosis before the age of five is difficult: in young children, in fact, the bronchial tubes become easily inflamed also due to acute viral infections, and the symptoms are similar. If the disease is particularly severe, the child may have a cyanotic complexion.
■ ECZEMA : also known as atopic dermatitis, it is a chronic-recurring inflammatory skin disease with itchy manifestations. The inflammation is such that the skin becomes hyper-reactive, so that chronicity is easily triggered. Symptoms: red skin, intense itching, fissures (sores) especially in the neck, armpits and groin; in the acute phase, also papules, vesicles and serous discharge.
■ URTICARIA : it manifests itself with the classic wheals, protuberances of the skin (from a few millimeters to several centimeters in diameter) surrounded by a reddish halo, which cause intense itching. If the extension is conspicuous, we speak of angioedema, frequent in infants at the level of the hands, feet, face and genitals. About one person out of five has an episode of hives in their life: in children the incidence varies from 5 to 7%, with mostly acute episodes; chronic urticaria affects only 0.2-1% of children. Causes: infections (often combined with antibiotic treatments) and, rarely, food allergies.
■ VOMITING AND NAUSEA: these are among the clinical manifestations of a food allergy. They can occur alone or, more often, associated with other symptoms.
■ ANAPHILAXIS: also known as anaphylactic shock, it is a rare and extreme manifestation of an allergic reaction, which appears suddenly and affects the whole body: blood pressure drops, heart beats increase, the larynx swells, breathing becomes difficult and a sense of suffocation is felt followed by paleness and loss of consciousness. To be addressed promptly.
SPRING ALLERGIES
Pollen allergies no longer strike only in spring but throughout the year, with a period of maximum diffusion of pollen which, according to the WHO, in Europe has extended by at least 10 days in the last 20 years. About 10% of children suffer from rhinitis and conjunctivitis when exposed to grass pollen. In addition to the classic symptoms, there are dark circles under the eyes and a characteristic horizontal fine line on the nose, the effect of the continuous upward rubbing. Hereditary and environmental factors combine to favor pollen allergies, which on average affect boys more.
FOOD ALLERGY
From the first months of life, food allergies can develop, which occur in 1-4% of children. Their severity varies, but they usually improve after age six. Food allergy is triggered following the ingestion of particular foods (and the allergens they contain), against which the immune system defends itself by producing specific antibodies; however, it should not be confused with intolerance, which is rather comparable to an intoxication. The most frequent allergies are caused by proteins found in common foods: milk, eggs, wheat, soy, fish (on average 3-6% of children suffer from it), peanuts, tree nuts, peaches, strawberries, tomatoes and, less frequently, olive oil, honey, celery, carrot, apple and apricot. The main manifestations can be:
■ gastrointestinal (vomiting, diarrhea, abdominal colic);
■ skin (urticaria, angioedema, atopic dermatitis);
■ respiratory (rhinitis, asthma), more rare;
■ anaphylaxis, more serious and very rare.
ALLERGY TO DUST MITES
Typical of closed, hot and humid environments, it very often affects children. In this case, prevention is essential to give relief to allergy sufferers, and it is also feasible: ventilate the child's bedroom for a long time, keep the temperature no higher than 20°C, remove curtains, carpets, books and soft toys and use mattress covers and special pillow covers, which trap the allergen, reducing its concentration in the environment.
THE TESTS
How are allergies diagnosed? First of all, by contacting the pediatrician, for whom a simple visit is enough to formulate a diagnosis, to be confirmed with specific tests capable of identifying the responsible allergens. The Prick test consists of skin tests: a drop of the allergen to be tested is applied to the skin and pricked on the drop (the procedure is safe and painless, therefore also suitable for children). If the subject is sensitized, his body will have produced the specific IgE and, in a few minutes, the characteristic red wheal will be produced (which will disappear within a few hours). The Rast test, on the other hand, searches for IgE in the blood and is used in cases of extreme skin reactivity to contact with certain allergens.
THE TREATMENT
The treatment of allergies par excellence is based on antihistamines: able to block the action of histamine, the molecule released during an allergic reaction, they demonstrate effectiveness above all against sneezing and nasal itching. For the treatment of nasal obstruction, topical corticosteroids can be used, which act at the level of the airways and have no side effects. The aforementioned drugs are used to treat allergies immediately; later, long-term treatment is often necessary to reduce sensitivity to the allergen and stop the progression of the disease: therefore immunotherapy is used (so-called vaccines), available not only subcutaneously but today also sublingually. To identify the correct treatment, it is essential to consult pediatricians and experts.
by Duccio Scarpelli | Taken from the magazine Nascere Mamma |
