Let's clarify what an allergy is and point out some allergy symptoms. An allergy is actually a physical response to certain chemical substances. In a sensitive person, the immune system erroneously identifies the harmless material as unsafe, reacting in opposition to it.
This specific unnecessary safeguard reaction can often be too extreme and also the antibodies generated to combat the substance possess annoying or perhaps harmful effects along with allergy signs or symptoms that will constitute the particular allergic reaction. More than likely, your own body can recall that compound, that's exactly, your own immune system memorizes that chemical and also translates this into allergic reactions in the long run.
Allergies tend to present themselves in families, which indicate a possible hereditary origin, but they are also caused by exposure to certain substances. The raising process can occur when there is a first contact with these substances, or when the contact is continued for a brief period of time or over several years. During this period, the immune system is activated and reacts against what, in general, is a relatively innocuous substance.
Allergies can show up at all age groups, but arise quite often in early child years, particularly contact allergies, which can be typical reactions to the very first exposure to the allergic substance.
Our immune system has a database of "strange" substances with which it already had contact and which response to produce when it detects it once again. Each and every time the allergen strikes, the immune system does respond by distinct memorized antibodies and yes, the allergy symptoms and reactions appear again!!
When you suffer from any allergies, contact with the irritating substance will unleash a variety of unpleasant allergy symptoms such as rash, itching or swelling, irritation or eye swelling, mucus, nasal inflammation, acute difficulty and hiss to breathe. Sometimes, an acute reaction may need immediate emergency treatment.
On first exposure to an allergen the immune system weakens. Subsequent exhibitions, is an allergic reaction that can go from a rash of various respiratory problems. There are several types of allergic reactions and vary from person to person.
We can then define the allergy as an exaggerated response of the immune system to a foreign substance to the body, i.e. a hypersensitive immune responses to a specific internal or external stimulus.
Allergic reactions may occur immediately (immediate hypersensitivity) such as the type most often called anaphylactic shock, or it may occur in a longer period, after the contact with the allergen (Delayed-type hypersensitivity),
The Delayed-type hypersensitivity divides into three major types: cytotoxicity, immune complexes , and Type IV or Cellular
The immediate Hypersensitivity occurs when a given individual produces large amounts of immunoglobulin E (IgE) in order to protect themselves from pollen grains, for example.
Mast cells (from the tissues) and basophils (from the blood) bind to IgE, causing it to avoid the release of histamine. This causes symptoms such as vasodilatation, inflammation and breathing difficulties. If an allergic reaction is not treated with an antihistamine, it can even lead to death in the most serious situations, and tests should be carried out for the detection of sensibilities.
1) Anaphylaxis or anaphylactic shock is a severe allergic reaction that occurs minutes after exposure to an allergen (approximately a quarter of an hour after). This reaction is mediated by certain substances such as histamine, in cells of the respiratory mucosa, intestinal mucosa and epidermis, and by certain white blood cells (mast cells and basophils). As the reaction progresses, some inflammatory substances with high power are synthesized. In an anaphylactic shock, in most cases, the individual becomes Livid with cold skin, feel an extreme anxiety, and may even faint
The delayed Hypersensitivity takes over 12:00h to arise to exposure to the allergen and to display allergy symptoms. In this case, the allergenicity is processed by antigen-presenting cells and starts a mediated response. This response can be so intense that the amount of cytokine freed is able to activate macrophages and injured tissues. (Ex: when bacteria that cause tuberculosis colonize lungs.)
2) Type II or cytotoxicity is a reaction which occurs, for example, in some autoimmune diseases such as thyroiditis, when a person forms antibodies against his own elements (organs and tissues). Good examples are: allergic rhinitis, certain types of acute bronchial asthma or allergic reactions to drugs.
3) Type III or immune complexes is a reaction characterized by the formation of Antigen-antibody complexes (immune- complexes), which deposited in tissues or enter the bloodstream. Immune-complexes attract mediators of inflammation, determining localized lesions in certain organs or spread throughout the body.More visible allergy symptoms!
4) Type IV or Cellular is a reaction mediated by lymphocytes and its products, the lymphokines, released by contact with the Antigen, whose typical example is the tuberculin reaction. The same mechanism as in transplant rejection and the so-called contact dermatitis.