Allergy also referred to as atopy is a disorder of the immune system by which the body produces elevated response against substances which are normally not recognized as foreign. The body usually produce have the ability to differentiate between harmful antigens and harmless foreign substances. Hence the body does not produce elevated responses against harmless substances that we come across daily. Shell fish, nuts, milk, dust, pollen grains, insect venom and wheat flour are harmless to the body and hence the body does not respond to it. But the immune system of some people recognizes these innocent foreign particles as invaders and reacts inappropriately producing allergic reactions.
In the attempt to protect the body from invaders, the immune system produces elevated concentrations of immunoglobulin Ig E. The allergy cells, mast cells and basophil are activated by the immunoglobulin produced and it in turn releases chemicals like histamine which fights against the allergen. The chemical released by the allergy cells of the body are responsible for the allergic reactions which affects the skin, nose, throat and gastrointestinal tract. Once the allergic responses are shown, the future exposure to the same allergen will trigger similar responses.
The presence of allergens in high concentration can lead to many allergic reactions in people. Allergy level means the concentration of an allergen like pollen, dust, dust mites or a particular protein in a food, on a location at a particular time. Knowing about the allergy levels of different allergens in an area can be helpful for those suffering from allergy to that substance in particular. Studies have shown that elevated allergen levels at home can cause asthma attack and other related allergic symptoms.
Some people may develop allergy to certain food which most other people eat without any difficulty. Proteins, macromolecule, certain additive or preservatives in the food may be the real cause of the allergy rather than the whole food itself. A certain level of allergen molecule should be present in the food to trigger the allergy. very low concentration of the allergen usually does not trigger response. In some cases cross contamination of food can also cause allergic symptoms if the level or concentration of the allergen molecule reaches the minimum level needed to cause the reaction. If a particular food item is manufactured in an industry where another food is also produced, the chance of cross contamination occurs. For example if a product is manufactured in same building processing peanuts, allergic reaction to peanut may occur by eating the other food.
The level of pollen concentration is at the highest during the spring when all the plants and trees are flowering. The most occurring allergic reaction to pollen is hay fever marked by stuffy nose, itchy and watery eyes, skin rashes and breathing difficulty. The level of pollen in the atmosphere can depend on the temperature, time of the year and the moisture in the atmosphere. Warm dry and windy climate can elevate the pollen level whereas moist and rainy climate can decrease the pollen level. The most effective way to prevent pollen allergy is to stay away from it, and it is easy to stay away from it if the level of pollen in the atmosphere is known.
Molds are a type of fungus found in soil air and moist area. Living or dead molds and mold spores can cause allergy and the symptoms of mold allergy includes running nose, coughing, sneezing and headache. Mold level in the atmosphere is rather high in the humid climate and in damp areas around the house.
Proper and effective treatments are not there for mold allergies so the best thing to do is to keep away from this allergen. Maintaining the indoor humidity below 50 percent can reduce the level of molds and hence the chance of allergy. Also avoiding foods like mushroom, or food containing yeast and food processed with fungus like cheese can reduce the occurrence of mold allergy.
Pollen and mold counts give us the approximate value of the allergens present at the certain time at the particular place. This count can give us the value for a single day and the count can change considerably each day due to the climate and temperature change. We cannot get the exact count on a rainy day as precipitation contaminates the count.
Pollen and mold allergy forecast can give us the general picture of the allergic reaction level on the day and the coming few days due to the change in the potency of the allergen namely pollen and mold. The chance in weather during the next few days will determine the levels of the pollen and molds in the atmosphere and hence the chance of allergy. The allergy forecast gives us a much more clear and accurate picture than the count method .
The allergy to any substance can be identified by skin prick test and blood test. Though skin test is the least costly and sensitive method to identify allergy, it cannot give the level of the immunoglobulin concentration in the person and hence the level of allergy.
RAST or radio allergosorbent test is a blood test which can be used to identify the concentration of allergen specific immunoglobulin (Ig E) produced in response to an allergen. The RAST test is scored on a scale from o to 6 where the score 0 shows no allergy to the specific allergen and score 4 to 6 shows high level of allergy to the particular antigen.