Allergies and Food Sensitivities

Food sensitivities, also known as non-allergic food hypersensitivities, refer to adverse physiological responses to certain foods that do not involve the immune system in the same way as food allergies. These reactions are often caused by enzyme deficiencies, chemical sensitivities, or irritants within the food, leading to symptoms such as gastrointestinal discomfort, headaches, fatigue, or dermatological reactions. Common triggers include lactose, gluten, food additives, and naturally occurring food chemicals like histamines. Unlike food allergies, which are IgE-mediated and can cause immediate and potentially life-threatening reactions, food sensitivities tend to produce delayed and less severe symptoms, making diagnosis more complex and typically reliant on elimination diets or specialized testing.

While the number of individuals affected by food intolerances has risen significantly in recent decades, not every reaction is due to an actual allergy. Food allergies are caused by an abnormal immune response—typically IgE- or IgG4- mediated—where the immune system mistakenly identifies a harmless food protein as a threat and releases histamines and other chemicals. This can result in immediate symptoms such as hives, swelling, wheezing, vomiting, or in severe cases, anaphylaxis, a life-threatening condition requiring emergency medical attention. Common food allergens include peanuts, tree nuts, eggs, milk, wheat, soy, fish, and shellfish.

Unlike intolerances, which are often dose-dependent and related to enzymatic or chemical reactions in the digestive system, allergies can be triggered by even trace amounts of the allergen. Moreover, allergic reactions typically occur quickly after ingestion, while sensitivity symptoms may be delayed. Some individuals may experience both types of reactions simultaneously, complicating the diagnostic process.

As specialists for food intolerances and allergies, we focus on differentiating between immunological and non-immunological reactions. Our interdisciplinary team—comprising dermatologists, pediatricians, environmental medicine specialists, psychologists, nutrition experts, and natural scientists—works collaboratively to uncover the root causes of symptoms. Through precise diagnostic tools, including allergy testing, food challenge procedures, and elimination diets, we develop personalized treatment plans to help patients manage their condition safely and improve their quality of life.

Allergy or Food Intolerance ?

Many people experience symptoms after consuming certain foods. These symptoms vary from person to person. For example, one person may suffer from severe migraines, another may experience gastrointestinal discomfort, while another may experience a rash or itchy skin. If these symptoms occur repeatedly when consuming certain foods, the symptoms can be classified as a food intolerance. It is estimated that around 20 percent of the population in industrialized countries is affected by such intolerance, but only a fraction of these symptoms are actual allergic reactions.

The difference lies in the involvement of the immune system: A true food allergy is a rapidly occurring, immunologic ally mediated reaction to otherwise harmless substances in food. This overreaction of the immune system to certain food components particularly affects peanuts, eggs, milk, fish, and wheat in childhood, while adults are particularly allergic to wheat, shrimp, hazelnuts, soy, celery, and peanuts. Even tiny amounts of the affected food can trigger severe reactions, including respiratory distress, in the case of an allergy.

If the immune system is not involved in these reactions, it is a non-allergic food intolerance, medically known as an intolerance (including, for example, intolerance to the sugars fructose or lactose). This can occur, among other things, when the intestine is unable to properly process or utilize certain food components, or when an abnormal intestinal flora uses the food for its own purposes. If these reactions occur late, it is no longer a food allergy, but a food intolerance. In this case, too, the immune system can be involved; typical examples are celeriac disease, gluten intolerance, or histamine intolerance.

In our everyday life as specialized clinic for allergies we also encounter numerous allergic reactions and food intolerance, but non-immunological reactions to food are also much more common. One of the best-known non-allergic food intolerance is lactose intolerance – here, a missing, defective, or regulated enzyme leads to the absorption of lactose. In other cases, the intestinal flora ferments the lactose to generate energy from it. The resulting substances lead to the typical associated digestive disorders. Fructose absorption, which is accompanied by unpleasant gastrointestinal reactions to fructose, is also one of these intolerance. In addition, foods with a high histamine content, such as long-aged cheeses or smoked fish, as well as red wine and sparkling wine, can trigger pseudo-allergic reactions in people with histamine intolerance, for example, rashes, diarrhea, or migraines.

As there are no two patients with the same spectrum of allergies and sensitivities against foods its easy to understand that only a personalized diet taking into acount the above mentioned reactions can insure a long term symptom freedom by strongly reducing inflammatory reactions in the gut, lungs or on the skin.

In this respect our German team developed for more than 30 years a personalized hypoallergenic rotation diet which eliminates the incriminated food allergens and offers the tolerated foods in a 4 day rotation system.

To understand the personalized treatment of allergic and pseudoallergic reactions against foods please review our original publication on this topic in the reference below.