Blood & Laboratory Values

Allergens – Function & Diseases


Allergens are antigens that trigger an unusually strong immune response in a person. The purpose of the immune response is to fight off a substance that is perceived as a threat but is normally harmless to the body. This hypersensitivity reaction to allergens is called an allergic reaction.

What are allergens?

Allergens are antigens capable of eliciting a type 1 hypersensitivity reaction in atopic individuals through immunoglobulin activation.

In most people, an immunoglobulin reaction only occurs in response to a parasitic infection. However, there are also people who react in this way to antigens that are common in the environment. This hereditary predisposition is called atopy .

In atopic individuals, non-parasitic antigens stimulate an abnormal elevation of immunoglobulin E antibodies, resulting in type 1 hypersensitivity.

The type of hypersensitivity varies from person to person (or animal to animal). A wide range of substances can become allergens for sensitive individuals. Known allergens are mite droppings, pollen, animal dander (cats, dogs, etc.), fungal spores, royal jelly, peanuts, hazelnuts, fish and seafood, eggs, milk, strawberries, wheat gluten, soy, perfume, food coloring, flavor enhancers, bee and Wasp venom, penicillin, wool, latex, nickel and formaldehyde.

Medical & Health Functions, Tasks & Meanings

The reasons why people develop an allergy to allergens can be found in their hereditary factors, personal habits and the environment. There is an indication that children who eat fast food frequently have a generally increased tendency towards allergies. The age of first contact with an allergen also plays a role: the earlier in life a person has come into contact with an allergen, the higher the probability that they will develop an allergic reaction to it at a later point in time. 

This is because the body’s immune system must develop a sensitivity to the allergen before one can become allergic to it. In other words, the immune system must recognize and “remember” the allergen and then make antibodies against it. This process is called sensitization. However, it takes different amounts of time to develop sensitivity to an allergen depending on the person. Some people do not get past the sensitization phase, and although they experience some symptoms related to the allergens, they never develop a full-fledged allergy.

Contact with an allergen is made through inhalation, touch, injection, or through food. In order to protect consumers with allergies, there are allergen labeling guidelines in Germany that determine which allergens must be declared on food packaging or at a sales stand. In 2006, the allergens that had to be labeled included e.g. E.g. celery, mustard, peanuts, crustaceans, mussels and cereals containing gluten.

There are also so-called pseudo-allergens that trigger allergy-like symptoms. These include cigarette smoke, lactose, fine dust, cleaning agents and ozone. Substances that never cause allergies are mountain air, pure water, fats, mineral salts and purified vitamins .

Illnesses, Ailments & Disorders

Typical allergic reactions to allergens cause irritation and inflammation in the body, resulting in swelling of the affected areas.


Symptoms can be:

In rare cases, an allergy can lead to a severe allergic reaction called anaphylactic shock  , which can be fatal. Usually, allergic reactions are localized to a specific part of the body, such as the B. the nose, the eyes or the skin. In anaphylactic shock, however, the whole body reacts allergically and this usually happens within a few minutes after contact with the allergen.

Anaphylaxis is divided into four degrees of severity:

Severity 1: sneezing, coughing, wheal formation, itching , reddening of the skin , edema , accelerated pulse.

Severity 2: anxiety , difficult breathing, stomach cramps , jugular vein congestion, drop in blood pressure.

Grade 3: severe drop in blood pressure, severe shortness of breath , seizures .

Grade 4: Pale or bluish skin, unconsciousness , no pulse felt.

When a person goes into anaphylactic shock as a reaction to an allergen, they need emergency treatment, in which they are injected with the drug adrenaline .

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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.