Food Allergy (Food Allergy) – Causes, Symptoms & Treatment

Food allergy (food allergy)

One speaks of a food allergy or food allergy when the body of the affected person reacts hypersensitively to various foods or foods. This leads to allergic reactions with typical signs and symptoms. Stomach pain , shortness of breath , asthmatic attacks , reddening of the skin , sneezing and a permanent runny nose are particularly characteristic. Since a food allergy can also lead to circulatory shock , a doctor should always be consulted at an early stage if there is any suspicion.

What is a food allergy?

One speaks of food allergy or food allergy when certain foods or components of the food cause an intolerance reaction. This can range from a mild skin rash to a severe allergic shock reaction.

However, not all food intolerances are allergies . About a third of adults think they are allergic to a certain food. A closer look reveals a food allergy in only 2% of adults. The remaining 31% is an intolerance caused by food poisoning , a psychological aversion to the food, or a food intolerance .


Compared to the other intolerance reactions, the immune system must be involved in the defense reaction in the case of a food allergy . A normally harmless component of the food, usually a protein, is viewed by the body as a supposed threat and triggers an immunological counter-reaction. Antibodies and messenger substances such as histamine are then produced. They are responsible for allergy symptoms such as itching of the skin and eyes, swelling of the mucous membranes in the mouth and nose, runny nose, allergic asthma, nausea or diarrhea.

The likelihood of developing a food allergy depends on family history. If one of the parents suffers from an allergy, the probability that the child will also develop an allergy is about twice as high. If both parents are allergic, the risk increases four to sixfold. Breastfeeding appears to protect against the development of food allergies. Studies show that infants who are breastfed for the first 4-6 months have a lower risk of developing allergies than infants who are formula-fed.

Symptoms, Ailments & Signs

A distinction must be made between food allergies (food allergies) and intolerance to certain foods or their components. The symptoms of both can be similar. Clear immunological evidence can be found for food allergies. Intolerances to food (components), on the other hand, are caused by the metabolism .

The symptoms of a food allergy can be complex. Allergic reactions often take place on the skin or mucous membranes. Possible skin reactions can include extensive reddening ( exanthema ), swelling or wheal formation and eczema . In other cases, or in addition to skin reactions, reactions in the gastrointestinal tract can occur with a food allergy. Unexplained stomach problems or diarrhea , abdominal cramps , vomiting or nausea occur .

Possible allergic symptoms can also include a runny nose, swollen airways or watery eyes. Sneezing attacks or a runny nose after eating certain foods can indicate food allergies. In severe cases, shortness of breath or asthma attacks can occur. All symptoms that take place in the oral cavity should be taken seriously. Swelling of the lips, tongue, or gums, with or without itching , can become dangerous.

In the presence of other allergies, the food allergies can represent a cross-reaction. In addition, allergy symptoms to food can be exacerbated by stress, exercise or alcohol. The greatest danger of food allergies is anaphylactic shock. This can lead to death.

course of the disease

The most severe form of complications can occur with a food allergy in the form of a severe allergic reaction or even anaphylactic shock . This is a total circulatory collapse that becomes life-threatening and requires immediate medical attention.

An example of a food that is capable of inducing anaphylactic shock is the peanut. The most common allergy-causing foods include nuts, milk, eggs, grains, shellfish, fish, and soy . But stone fruit, celery and buckwheat also lead to allergic reactions in some people.

In the case of food intolerance, such as lactose intolerance , the immune system remains uninvolved. In the case of lactose intolerance, the intolerance reaction is triggered by the lack of the digestive enzyme lactase. This enzyme is responsible for breaking down lactose. If it is missing, the lactose reaches the lower parts of the intestine undigested and causes flatulence and diarrhea there.


As a rule, a food allergy always leads to very unpleasant symptoms. The quality of life of the patient is reduced by this allergy and there are various limitations in the patient’s everyday life. Those affected primarily suffer from abdominal pain or stomach pain. It can also lead to vomiting or diarrhea.

Not infrequently, a food allergy also leads to an itchy rash on the skin. As long as the person concerned does without any critical ingredient, the symptoms usually do not occur and there are also no special complications. This means that the food allergy can be limited relatively well and easily.

Furthermore, the food allergy can also lead to a loss of appetite and thus to weight loss or various deficiency symptoms. A direct treatment of the food allergy is usually not possible. The symptoms are limited and reduced by a strict diet.

However, a completely positive course of the disease usually only occurs if the patient abstains from the triggering substance. In most cases, the life expectancy of the patient is not affected or reduced by the food allergy.

When should you go to the doctor?

Food allergies are relatively common, but they are not always a reason to see a doctor. Symptoms that appear for the first time should be examined by a doctor and the food allergy diagnosed. However, going to the doctor is only important in certain cases.

These include allergies, the symptoms of which are so pronounced that they can become life-threatening. An example of this are patients in whom an allergy to nuts or fruits leads to a local reaction in the oropharynx. This can cause swelling that greatly hinders those affected from breathing. Anaphylactic shock can also be a serious complication, so that these patients need consistent medical treatment due to the intensity of their allergy.

Allergy sufferers whose digestive tract is severely affected should also speak to a doctor. This can be the case, for example, if cow’s milk protein or gluten from wheat is not tolerated. These are usually not life-threatening phenomena. However, if the restrictions on quality of life caused by weight loss, pain or flatulence become too great and persist, it makes sense to go to the doctor.

Treatment & Therapy

A food allergy is diagnosed using a skin test or an oral challenge test. In a skin test, the alleged allergy-causing substance is introduced into the skin. If an allergy is present , reddening , itching and swelling occur in the affected area . However, the value of this test is not 100% reliable.

In the oral challenge test, the patient has to swallow a capsule containing either the allergy-triggering substance or a placebo. Subjective misjudgments are avoided via the placebo control. However, the allergy-triggering food must be known for this test. Most of the time this is not the case. A food exclusion process helps identify the appropriate food. Eligible foods are removed from the menu for about two weeks. If intolerance reactions occur again when the food is reintroduced, this is a sure indication of the presence of an allergy .

However, once the diagnosis has been made, there are no treatment or cure options. Only avoiding the corresponding food protects against a new intolerance reaction. It is important to ensure adequate nutrient intake despite not eating the foods in question. In the case of a cow’s milk allergy, care must be taken to ensure adequate calcium , vitamin D and protein intake through alternative foods.

Outlook & Forecast

The prognosis of a food allergy is unfavorable. In most cases, an allergic reaction lasts for life. However, there are numerous therapeutic approaches and alternative methods that can lead to significant relief and even freedom from symptoms. Depending on the individual allergic reactions and triggers of the allergy, avoiding the corresponding stimulus can lead to permanent relief of the symptoms. Therefore, some of those affected can make a significant contribution to their recovery without medical treatment.

However, most patients experience changes in the stimulus-triggering substances over the course of their lives. Often the number of foods that cause physical discomfort increases. Therefore, in addition to regular check-ups, there should also be sufficient information about cross-allergies and immediate measures. In severe cases, a food allergy can be fatal. The more often complaints occur, the more difficult it is to organize your life. Mental resilience increases and there is a risk of secondary diseases.

The circumstances described must be taken into account when making an overall prognosis. Close cooperation with the doctor is recommended, so that medical treatment can be initiated at any time if symptoms and irregularities increase. For some patients, lifelong therapy is necessary to prevent acute situations from developing.


It is known from small children that the food allergy is usually only present up to the age of seven and then goes away on its own. Follow-up care after recovery is unnecessary because experience has shown that no further complaints are to be expected. The situation is different in the years before enrollment. Follow-up care aims to avoid complications. Parents are primarily responsible for this.

Because you have to consider a few things when choosing food. Above all, allergy triggers should be avoided. Parents should always carry an emergency kit with them to prevent acute seizures. The doctor treating you informs the legal guardians as part of the initial diagnosis. Sometimes it can be useful to take part in a nutritional consultation.

The implementation of the nutritional information is then the responsibility of the mother or father. Adults can also suffer from food allergies. However, they usually require lifelong follow-up care because the intolerance reaction does not go away.

The same requirements apply to them as to children. However, they are responsible for avoiding the triggers themselves. Scheduled examinations are usually only usual if the state of health deteriorates. A skin test and a blood test then provide clarity about a reaction change.

You can do that yourself

The most important thing in everyday life for allergy sufferers is to avoid the relevant foods and their traces. Depending on the food in question, this varies in difficulty. A general cereal intolerance is more far-reaching than a celery allergy . It is important for sufferers to find a diet that is sufficiently balanced, tasty and fulfilling.Avoiding large food groups makes this difficult, but with a little research and the willingness to try new foods, a good diet can be found for everyone. Clues can be eating habits from completely different countries, which are often characterized by a completely different composition of food.

Food allergies should also always carry an emergency kit with them, as it can never be ruled out that they will come into contact with an allergen. In order to maintain personal well-being, it does not make sense to forego all major events, etc., because there could be an allergen source somewhere.

In the private sphere, the person affected by a food allergy can sufficiently enlighten his or her environment so that consideration is given to possible events. For people who generally think that allergies are imaginary or who try to put them into perspective by referring to small amounts, showing the emergency kit may be enough.

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.