The type of allergic reaction depends on the type of allergen and the way it enters the body or has contact with it. For example, an inhaled allergen like polen will cause reactions of the respiratory system, not the skin, but if an allergen reaches the blood system (by injection or ingestion), it can cause an allergic reaction anywhere on the body.
Therefore, allergen is a term used to define the source of the allergy, in various forms: for example, the cat, its dander, the allergy-triggering protein in the dander (Feld1).
The allergic reaction occurs when the allergen gets into the body (ingestion, injection or inhalation) or is applied on the skin.
The air contains numerous particles that can cause allergies (hay fever, asthma, eyes allergy):
Certain foods or medications can also cause allergies. When ingested, the allergens reach the circulatory system and can cause reactions in different parts of the digestive system: tongue or throat swelling, nausea, stomach ache, diarrhea, or also breathing problems or skin reactions.
The two main allergen groups are
Some foods are more likely to cause allergic reactions: milk, eggs, peanuts, wheat, etc. Also foods that contain these ingredients can cause allergies (sauces, mayonnaise, even cosmetics) or that have been in contact with them (ice-cream, chocolate).
Some allergens can cause allergic reaction after contacting the skin, for example, allergic dermatitis, or rash. Examples of allergen sources:
When injected, allergens can cause severe reactions, because they reach the blood system very quickly. Such a reaction involves a series of events that affect more organs at the same time and can cause the organism to get into shock (anaphilactic shock) and in the worst case, death. The most severe such allergens that get into the blood stream can be:
Allergy in a nutshell