When you are allergic to a certain type of allergen, you will experience an allergic reaction every time you come into contact with it.
There are two most common types of allergic reactions: those that are caused by antibodies and those that are caused by cells.
Anaphylactic shock is a severe allergic reaction that can have life-threatening issues. A severe allergic reaction can cause anaphylactic shock. The onset time varies from seconds to minutes or even hours after being exposed to the allergen, resulting in a rapid drop of blood pressure, accompanied by a feeling of dizziness, and even to the extent of unconsciousness and breathing difficulties.
The most common allergens are food and insect venom (wasps).
The body's immune system produces an antibody called immunoglobulin E (or IgE) that specifically targets allergens. When the immune system produces antibodies, it will enter various systems in the body through the blood, such as the skin, trachea, and stomach. These sites contain mast cells, specifically subcutaneous, and there are IgE receptors on the surface of mast cells, which bind to IgE in the blood. Mast cell activation is triggered when an allergen comes into contact with IgE antibodies on the surface of mast cells. The active mast cells will release some inflammatory factors (such as histamine, leukotriene, etc.), causing the patient to have allergic reactions, such as vascular leakage, vascular dilatation, itching, tracheal constriction and so on. This reaction can take place in a short period of time, such as minutes to hour. Nasal allergies, asthma, urticaria, rubella, acute food allergies, drug allergies, insect allergies, etc. are all caused by type 1 allergic reactions.
T cells of the immune system are sensitive to certain allergens, and when T cells are exposed to such allergens again, they release factors that cause an inflammatory response. A delayed allergic reaction usually occurs within 24 to 48 hours of exposure. Delayed allergic reactions can cause skin eczema, contact skin sensitivity, or food-induced gastrointestinal sensitivity.
Allergy Test
Allergy Drug
The same goes for taking allergy medication. It is very important to take note that different allergy mechanisms utilise different treatments. Failure to do so can lead to errors in diagnosis or treatment.
Epinephrine Pen
Desensitisation Immunotherapy
Immunotherapy is currently the only cure for allergies, targeting the cause of the allergy to desensitise it. Desensitisation immunotherapy (sublingual/injection) contains a specific amount of allergens to help patients gradually build up the immune system. After a period of immunotherapy, when the patient is being exposed to the same allergen again, the allergic reaction will be greatly subsided. In other countries, especially in Europe, desensitisation therapy is becoming more common.