Tiny amounts of the food in question are often enough to trigger an allergic reaction.
In surveys, 30% of the Swiss population claim to be allergic to foods. However, the proven level is only 2–6%. Most commonly infants develop food allergies, build up tolerance as they get older and often are able to tolerate the foods again.
A food allergy is based on an immune reaction by the body to harmless vegetable or animal proteins (allergens). The IgE antibodies trigger an allergic reaction with every contact – often tiny amounts of the food in question are enough.
Common and harmless reactions become noticeable in the mouth area: itching of the lips and throat, a furry feeling in the mouth and palate, swelling of the lips and tongue, the lining of the cheeks and throat immediately after eating the food. These symptoms are combined under the heading of “oral allergy syndrome”. Other possible reactions: vomiting, stomach or abdominal cramps, diarrhoea. Skin reactions (eczema, urticaria), asthma attacks, general feeling of weakness/asthenia, fall in blood pressure, palpitations through to anaphylactic shock are other possible symptoms.
Self-monitoring ideally recorded in a “symptom diary” and the results of skin test and blood tests form the essential foundation of the diagnosis of a food allergy. In addition, provocation (or challenge) tests may become necessary. Allergy tests can be carried out in babies over the age of 6 months. For “Differential diagnosis“ look here: Food intolerances
Strict abstinence is important, i.e. eliminating the allergy-causing food from a person’s diet. It is also essential to watch for concealed sources in bakery products, sausage, spice blends and semi-cooked and ready foods. In Switzerland, 14 ingredients that may cause an allergy or other adverse reactions must be clearly labelled and highlighted on the packaging (e.g. in bold type, italics or in capital letters). Unintentional mixtures/combinations must also be mentioned at the end of the list as follows : “may contain …” or “may contain traces of …”. Sales staff in shops selling food (e.g. bakeries, butcher’s etc) and in restaurants, takeaway kiosks etc must also provide information. By law, information supplied verbally by a professional is adequate.
Anyone who has already suffered a severe allergic reaction should always carry an emergency medical ID card and an emergency kit. If a new, severe allergic reaction occurs, an emergency doctor or a hospital should be consulted. SOS capsules are not very well-known in Switzerland, but they can be helpful.
Specific immunotherapy with food allergens is not yet available. There are on-going studies attempting to develop oral tolerance in people with food allergies. There has been some initial success, but no treatment can yet be offered to sufferers in clinical practice.
Adults are most commonly allergic to hazelnuts, celery, apples, walnuts and kiwi fruits. Particularly severe allergic reactions are triggered by peanuts, seafood or kernels and sesame seeds. Children typically react to cow’s milk, hen’s eggs, peanuts and other nuts.
Cross-reactions between birch pollen and raw stone and pip fruit are common, but can often occur between mites and seafood as well as latex and exotic fruits.