Etiology

    Scientists today may understand much about our immune system due to research into complex diseases that can affect it. Although with all the knowledge they have on our immune system they still do not fully understand why allergies develop in one person and not another. They also cannot answer many question one has about allergies such as Why do I have allergies? Why is my immune system so out of whack? Why is it that I become hyper vigilant and hypersensitive to substances like perfume or milk ?

    In this section we will talk about the major factors, of what causes allergies.

Too Much Musty Air

    Most people know about the pollen triggered allergies, few seem to know about other environmental factors which appear to have the same effects some not as bad, some more severe.
    Too many airborne allergenic pathogens such as dust mites, mold, yeast , algae, and spores in a home can trigger allergy symptoms.
40 % of all airborne allergy sufferers are particularly susceptible to pet dander. Domestic pets such as dogs and cats release dander - a mixture of small particles of fur, skin flakes and saliva) when they shed of groom themselves.
    These allergens disrupt our immune system causing hypersensitivity - undesirable (damaging, discomfort producing and sometime fatal) reactions and hyperactivity - immune system ties to do too much to fight foreign substances making out immune system unable to differentiate between harmful and benign substances. 

Genetics

    Genetics seem to play a big role in most people who appear to suffer from allergies. This doesn’t mean we are allergic to the same things our parents are only that they passed on some kind of immune system defect or weakness which makes us more susceptible or vulnerable to allergies.
It seems children with parents who have allergies are much more likely to be born with allergies or to develop allergies then children whose parents don’t have allergies.
    A study done of 344 families found that when neither or the parents had a history of asthma, only 6 percent of children actually developed it. In families where one parent had the condition, 20 percent of children had developed it and in families where both parents had it, the percentage shot up to 60 percent of their children having it too.
    A study done on identical and fraternal twins found that when one of the identical twin had hay fever, asthma or eczema, the other twins likely hood of having it was 50 to 80 percent. In the fraternal twins the percentages dropped considerably lower to about 25 to 40 percent. 
 

Foods

If someone is introduced to a certain food (such as strawberries) at too early an age, the immune system can develop an allergy toward it as it tries desperately in its early developmental stages to adapt to it. Because of this, at a later age, if that person comes in contact with the aforementioned food, their immune system may react radically to it and the individual may suffer an allergic reaction.

Antibodies (what your body produces to ward off an offending substance) called immunoglobulin (IgE) are released into the bloodstream when a food substance previously distinguished as an allergen is introduced to the body. These release potent chemicals (usually in great quantaties) that can effect us in negative ways. Histamine in particular causes the inflammation and swelling associated with hives.

While these symptoms can take as long as a couple of hours to take affect, people with particularly severe food allergies can feel the effects within minutes or even seconds. They may even be effected by inhaling the particles of a food they are allergic to.