ALLERGY

Allergy is a term generally used to described an adverse reaction by the body to any substance ingested by the infected individual. Strictly allergy refers to any reactions incited by an abnormal immunological response to an allergen, susceptibility has a genetic component. Most allergic are liked to atopy. The predisposition to berate the allergic antibody immunoglobulin E to common environmental agents.
Immunoglobulin E (IGE) is a type of antibody that is present in minute amounts in the body but plays a major role in allergic diseases. IgE binds to allergens and trigger s the release of substance from mast cell that can cause inflammation.(a mast cell also known as  mastocyte or a labrocyte) is drives from the myeloid stem cell. It is part of the immune system and contains many granules rich in histamine and heparin. Although best known for their role in allergy and anaphylaxis. Mast cell play important  protective role as we'll, being intimately involved in wound healing, including angiogenesis and also defense against pathogens. The mast cell is similar in both appearance and function to the basophi<another type of white blood cell. They differ in that mast cells are tissue resident e.g mucosal tissues, while basophils are found in the blood). When IgE binds to mast cells , a cascade  of allergic reaction can Begin

Binding of IgE to mast cells
 The surface of mast cells contain special receptor for binding IgE. The IgE antibody fits to this receptor like a module docking with the mother ship. This  arrangement is such that when two adjacent mast cell linked IgE antibodies are in place, the allergens is drawn to both and attaches itself to both, crosslinking the two IgEs. When a critical mass of IgEs become cross linked, the mast cell releases histamin and other inflammatory substances, and the allergic cascade begins.

The Allergic cascade pathway
Following exposure to an antigen, a series of initial reactions in the immune system occurs. This early phase response is followed by a second , more severe reaction known as late- phase response.
The following are the pathways
1) sensitization to  an allergen
2) early phase response upon re-exposure to an allergen
3) late-phase response to allergen

1) sensitization to an allergen: type1 allergies and anaphylaxis
 If  a certain substance in your diet or envir consistently triggers an acute, measurable immune response, you have what is known as typ1, of immidiate-reponse allergy. Type 1 allergic response are what most people (and doctors) refer to when they talk about allergies. Elevated levels of antibodies called IgEs in the blood stream trigger a histamine reaction. Itching watery eyes, runny nose, gives, itchy rash, swelling scratching throat,wheezing and coughing. Hay fever and some food allergies are type 1 allergies. The conventional treatment protocol is to manage these symptoms with avoidance of steroid, or anti-allergy medication s like claritin and allerra.
   Routs to exposure to allergen
a) inhalation (of pollen, mold, dust, mites etc.)
b) ingestion (swallowing a type of food or medication. E.g children taken drugs when      there ward is not around).
c) Touch (coming in contact with toxic substance, like poison)
d) injection (receiving  a medication or being stung by an insect).
   Reaction
The body produces IgE designed specifically for that particular allergen, the reaction will not be known by the person, until the person becomes atopic (I.e you've inherited a predisposition toward allergic disease). After then the T-cell quickly stimulate the B-cells.
The B-cell been stimulated developed into plasma cells. The plasma cell responsible for the production of immunoglobulin, produces immunoglobulin E, (IgE) antibodies which is targeted to that specific allergens. The IgE  binds to special receptor on mast cells which lead to sensitization.
2) Early Phase responds upon re-exposure to an allergen
                         When re-exposed to allergen, the IgE of mast cell binds to allergen, crosslinking the IgE.when enough crosslinking have been established, the mast cells explode with histamin and other inflammatory substances, called mediators. The mediators speed through the system,when this occurs symptoms like wheeze, cough, get itchy eyes have a runny nose, become short of breath. in other words,  experiencing the whole unpleasant range of symptom known as allergic response.this set of reaction occurs within an hour after  initial exposure.
3) Late-phase response to allergen
 The late phase respond actually begins at the same time as the earl-phase responds, but it takes longer to dee.  In dome individuals, the body rallies the immune system for this second phase, which can happen happen relatively soon after the initial reaction. Anywhere from  3-10 hours later. Often this late phase response involves immune cell known as eosinophils and it can last for 24 or so before subsiding. During the late phase response, congestion and certain other symptoms can be more sever than those seen during the initial response.
 Consequences of chronic allergic reaction in asthma
            With repeated allergen exposure and allergic response, some damage can be done to the tissues involved. To rwamedy this damage, researchers are exploring the issue of airway remodeling, or scarring of the airways in the lungs of asthma patients. Long ter controller medication that aggressively attack inflammation and maintain maximum lung function are also believed to reduce the risk of permanent damage.
Although allergic disease is not curable, it is treatable enough to love with. Healthcare providers can be significant allies in effort, particularly allergist s, pulmonologist and certain specialists..
 Source ndbestpromis@yahoo.com