Asthma has become a crucial health issue. In most major industrialized countries, the amount of individuals with asthma increases annually. In america, the incidence of asthma has doubled in the past two decades. However, less attention is paid to the incidence of allergies normally, with asthma as the most intense form.
Allergy
It “strikes” are triggered by contact with an allergen. In the classic case of hay fever, the allergen is a protein in the pollen particle. Although asthma is classified as a kind of allergy, attacks may be triggered not only by common allergens but by anything that irritates the lungs–particularly fine particulates from fossil fuel exhaust. A
llergies and asthma, known as type 1 hypersensitivity, are immune responses to otherwise “benign” substances. Your body responds as though it were under attack. Allergy symptoms are your body’s effort to eliminate the invader. Being allergic will run in families–if your parents have allergies, you are more likely to have allergies.
Good to know
However, you may not be allergic to the same things. What you inherit is an immune system which tends to overreact. And if you are allergic to a thing, you are more likely to be allergic to other people. This notion led Dr. Samuel Arbes and his colleagues to investigate whether the increase in asthma is from more contaminants or increased sensitivity. Are more people having allergic reactions simply because there’s more stuff ? Or are we getting more sensitive to our surroundings?
The Arbes study was restricted and only provides partial responses, but it strongly suggests that we are in reality becoming more allergic to our surroundings. The study’s findings are consistent with similar studies in Japan, the United Kingdom, and Denmark. Arbes looked at statistics from both latest National Health and Nutritional Examination Surveys–known as NHANES II and NHANES III–ran from 1976 to 1980 (NHANES II) and from 1988 to 1994 (NHANES III). NHANES II and NHANES III each ran allergy skin tests for common allergies.
Take note
Only six were the exact same in both polls: ragweed, rye grass, Bermuda grass, oak, cat dander, as well as the fungus Alternaria alternata that is common on plants and plants. What Arbes discovered was that the proportion of those who reacted to at least one of these pollutants doubled between NHANES II and NAHANES III.
And the percentage of those who reacted to all the individual allergens increased from a low of 2.1 times for ragweed to a high of 5.5 times for cat dander. There’s absolutely not any sign that our exposure to one of these allergens has improved. The growth can only be explained by an increase in sensitivity. The implication for asthma is that even though our vulnerability to environmental triggers like air pollution has improved, our susceptibility has also improved.
Why have we become more sensitive? Type 1 hypersensitivity (allergy) is an immune reaction. The job of the immune system is to recognize unwanted substances and organisms and stop them from doing damage.
Immune system
Antibodies are a familiar part of the immune system. They’re a type of memory of undesirable organisms. Specialized white blood cells known as B cells (because they are produced in bone marrow) create antibodies that recognize an invader like a virus. The antibody latches on the virus and brings macrophages (another sort of white blood cell) that destroy the virus. Antibody production is orchestrated by another sort of white blood cell: a type 1 helper T cell (made in the thymus) also called a TH1 cell.
This traditional immune response is typically accompanied by inflammation. The objective of inflammation is to mobilize the immune system’s resources. When the endothelial cells that form the outer surface of a tissue feel a foreign substance, they send out chemical signals called cytokines. In sending the signal, three things occur that make up the inflammatory reaction: – blood flow increases to the tissue; – white blood cells are attracted to the site; and – the small blood vessels (capillaries) that provide the tissue become more permeable, allowing white blood cells to get into the tissue.
Antibodies
Antibodies are made from biochemicals known as immunoglobulins. The three most frequent immunoglobulins are designated IgG, IgA, and IgM. IgG is present throughout the human body and composes 75 percent of all immunoglobulins. IgA is in mucous membranes. IgM is in blood. The principal antibody in type 1 hypersensitivity is IgE, a small portion of total immunoglobulin. Unsurprisingly, it’s located primarily in the cells that come into contact with the exterior –mucous membranes and skin.
When your sinuses, lungs, gut, or skin contacts an allergen, IgE acts toward the contaminated protein as an antibody would toward a virus: it latches onto it and activates an immune reaction by mast cells, another technical white blood cell. Mast cells are fat with histamine granules–“mast” means “well fed” in German. When triggered by IgE, mast cells degranulate, releasing histamine.
Inflammation
This causes inflammation. Like IgE, mast cells are focused where your body meets the exterior mucous membranes and skin. As an antibody”recalls” a virus, an allergen-specific kind of IgE”recalls” that allergen. The more exposure to an allergen in the environment, the more inflammation and allergy symptoms happen. Unlike antibody-mediated reactions, IgE-mediated reactions don’t involve B cells. But the process is orchestrated by a type 2 helper T cell (TH2 cell). IgE’s principal function in the normal function of the immune system is in protecting against parasites. In areas where parasites such as hookworm are typical, blood levels of IgE are 100 times larger than in areas low in parasites. In a sense, an allergy attack occurs when your immune system errors an allergen for a parasite.
Theories
Two theories have been offered to explain the rise in allergic sensitivity: the hygiene theory and the ecological stressor theory. Proponents of the hygiene theory originally argued that Western cultures have sanitized their surroundings so much that their immune systems do not develop correctly. That is, early exposure to allergens and pathogens helps build resistance and reduced rates of allergy. While plausible study supports the concept, many critics point out important cases where it doesn’t hold up.
For instance, the higher rate of asthma among minority populations (unless one assumes they are more sterile simply by virtue of the race) and the higher rate of asthma in”filthy” urban populations when compared with the “clean” suburbs. And while rural levels of allergies tend to be lower than urban rates, the reverse is true for infectious disease.
To put it differently, the hygiene theory would indicate that gap in antibody and allergy immune reaction are the same, but they are not. According to Garry Hamilton in NewScientist, this has led some investigating to rethink the hygiene theory. The current version claims that it’s exposure to certain benign germs that trains the allergy immune reaction. Rural kids have those flaws, while urban kids don’t.
T-Cells
Attention has turned to some other type of T cell known as a suppressor T cell (TS mobile ). Before the recent discovery of the Ts cell, immunologists believed that TH1 and TH2 cells needed to be pressured into action. However, it seems that in fact they need to be held back by Ts cells (hence suppressor T cell). If suppressor T cells are underdeveloped, another T cells can escape control. And contact with benign microorganisms appears to have something related to suppressor T cell growth.
The concept that environmental stressors actively and permanently disrupt our immune reaction is just as much a match since it’s an alternative to the hygiene theory. Air pollution has received substantial attention as an environmental stressor. The evidence indicates that various types of air pollution not only cause asthma attacks, but change the immune system in a manner that boosts the IgE-mediated allergic reaction.
Homeopathic remedies
For overall and specific allergens are available over the counter. And conventional techniques such as a neti pot that keeps sinuses moist helps support your body’s first line of defense.
