Allergens are antigens that trigger an unusually strong immune response in a person. The immune response serves to fight a substance perceived as a threat that is normally harmless to the body. This hypersensitivity reaction to allergens is called an allergic reaction.
What are allergens?
Allergens are antigens that are capable of triggering a type 1 hypersensitivity reaction in atopic individuals through immunoglobulin activation. In most people, an immunoglobulin response occurs only in response to parasitic infection. However, there are individuals who have such a response to antigens commonly found 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 nature of hypersensitivity varies from person to person (or animal to animal). For sensitive individuals, a wide range of substances can become allergens. Known allergens include mite feces, pollen, animal dander (cats, dogs, etc.), fungal spores, royal jelly, peanuts, hazelnuts, fish and seafood, eggs, milk, strawberries, wheat gluten, soy, perfume, food dyes, flavor enhancers, bee and wasp venom, penicillin, wool, latex, nickel, and formaldehyde.
Medical and health functions, roles and meanings.
The reasons why people develop allergy to allergens can be found in hereditary factors, personal habits as well as the environment. For example, there is an indication that children who frequently eat fast food have a generally increased tendency to develop allergies. The age of first contact with an allergen also plays a role: the earlier in life history a person came into contact with an allergen, the higher the probability that he or she will develop an allergic reaction to it at a later stage. This is because the body’s immune system must develop 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 develop 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 stage, suffering some symptoms related to the allergens but never developing a full-blown allergy. Contact with an allergen is made by inhalation, touch, injection, or through food. To protect consumers with allergies, Germany has allergen labeling guidelines that determine which allergens must be declared on food packaging or at a point of sale. In 2006, allergens requiring labeling included, for example, celery, mustard, peanuts, crustaceans, shellfish and gluten-containing cereals. 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 trigger allergies are mountain air, pure water, fats, mineral salts and purified vitamins.
Diseases, ailments and disorders
Typical allergic reactions to allergens cause irritation and inflammation in the body, resulting in swelling of the affected regions. Symptoms may include:
- Nausea, vomiting and diarrhea
- Runny nose, sneezing
- Pain or pressure in the sinuses
- Itchy or burning eyes, ears, lips, throat and palate.
- Swelling of the mucous membranes
- Skin rashes
- Cough
- Whistling breathing or wheezing
- Shortness of breath
In rare cases, an allergy can lead to a severe allergic reaction called anaphylactic shock, which can be fatal. Normally, allergic reactions affect a localized part of the body, such as the nose, eyes or skin. However, in anaphylactic shock, the whole body has an allergic reaction, and this usually occurs within minutes of contact with the allergen. Anaphylaxis is divided into four degrees of severity:
Severity 1: sneezing, coughing, wheal formation, itching, redness of the skin, edema, accelerated pulse.Severity 2: tremors, difficult breathing, stomach cramps, neck vein congestion, drop in blood pressure. Severity 3: severe drop in blood pressure, severe shortness of breath, seizures. Severity 4: Pale or bluish discolored skin, loss of consciousness, no palpable pulse. If a person goes into anaphylactic shock as a reaction to an allergen, then they need emergency treatment in which they are injected with the drug epinephrine.
