Food allergy

In a food allergy, the immune system overreacts to what should be harmless proteins in a food. It is one of the immediate-type allergies because symptoms appear within a short time after eating a food and can worsen quickly. It may be caused by a congenital predisposition to allergies. Sometimes, however, a food allergy occurs out of the blue - regardless of age - even though you have always tolerated the foods in question well before.

There are two types of food allergies:

• primary food allergy: Here, the allergic reaction occurs directly in connection with the allergenic food. Food allergies of the primary type usually occur in early childhood. According to the Allergy Information Service of Helmholtz Zentrum München about 3 percent of the adult population is affected, and 4 to 6 percent of children. Children have a greater chance that the allergy will regress later.
• secondary food allergy: Here there is a cross-reaction, i.e. it is often a concomitant of hay fever. The original allergens are often pollen that lead to a cross allergy to certain foods due to a similar allergen structure. Those who react to birch pollen with hay fever might also develop symptoms with apples and hazelnuts. However, the symptoms are often less pronounced than in the case of a primary food allergy.

In addition, there are a number of food intolerances, but most of them are not true allergies. Often, certain food components are not properly processed here in the digestive system due to a lack of special enzymes or a functional disorder. Common intolerances - also called intolerances - are:

• Lactose intolerance
• Histamine intolerance 
• Fructose intolerance
• Gluten intolerance
• Glutamate intolerance

Mostly it comes here to gastrointestinal problems, headaches or fatigue. The complaints do not necessarily occur immediately after eating the food. Therefore, it is not quite easy for affected persons to understand which food they do not tolerate. In order to facilitate the diagnosis, it is advisable to keep a food diary.

Foods that often cause an allergic reaction are:

• Dairy products
• Nuts (nuts)
• Eggs
• Raw fruits such as apples, strawberries, kiwi
• Raw vegetables such as carrots, tomatoes, peppers
• Gluten-containing grains such as wheat, rye, barley, oats
• soy and soy products
• fish
• crustaceans and crustacean products
• celery
• mustard
• sesame seeds
• lupins
• mollusks such as snails, Mussels, squid
• Preparations to which sulfur dioxide or sulfites are added

Often allergy sufferers react to several foods at once. Raw fruits and vegetables can become more digestible when cooked. With apples there are also differences between the varieties. Old varieties such as Boskoop, Gravensteiner and Jonathan are usually better tolerated by allergy sufferers than newly bred apple varieties such as Gala, Golden Delicious and Granny Smith.

As a rule, the consumption of a food causes discomfort within a few minutes to several hours afterwards, which can also be very severe in the case of nuts and shellfish. Sometimes it is enough if a food that is actually tolerated came into contact during preparation with a knife that was previously used to cut the food that causes the allergy. With an allergy, the following symptoms can occur:

• Tingling on the tongue
• Itching in the mouth and throat
• Scratching in the throat
• Flowing nose
• Breathlessness
• allergic asthma 
• Swelling of the tongue, lips or face
• Swelling of the hands and feet
• Puffy eyes
• allergic conjunctivitis 
• skin rash 
• heart palpitations
• circulatory problems
• sweating
• abdominal cramps
• nausea
• vomiting
• diarrhea

After about 6 to 24 hours, a second wave of allergy is possible, a so-called late reaction. In some cases, even contact with a food is enough to trigger itching or swelling of the skin. Often the symptoms improve after a few hours. However, food allergy can also lead to anaphylactic shock, which can be fatal if left untreated.

Since the symptoms of a food allergy can be unpleasant to dangerous, great caution is called for in any case when eating food. What you should absolutely consider to avoid an allergic reaction:

• By an allergy test  you can get to the bottom of the allergens. Above all, you learn thereby also, whether possibly a cross-allergy exists.
• Avoid absolutely all foods that lead to allergic reactions with you.
• When buying finished products, always pay attention to the ingredients and manufacturer information. Because often allergens are hidden here, which at first glance no one would have expected. If, for example, nuts trigger violent reactions, the notice "May contain traces of nuts" can be lifesaving for you.
• It's best to do without industrially manufactured products altogether and prepare your meals yourself.
• If you are invited to dinner, find out in the restaurant or from the host, whether foods were used in the preparation, to which you are allergic.
• Also pay attention to medicines, whether allergens are possibly hidden in them.
• ask your doctor whether there is the possibility of hyposensitization. This can permanently alleviate or eliminate the symptoms.

If, despite all caution, an allergen has strayed into your diet, fast action is advised. Because a food allergy can lead in the worst case to an anaphylactic shock, which must be urgently cared for by an emergency physician. If you have known about the food allergy for some time, you ideally have your emergency kit with you, with which the treatment can be carried out immediately.