Variety of tests now exists to diagnose the allergic conditions; it include testing skin for the responses to known allergens or analyzing blood for presence and the levels of allergen-specific. Originally, concept of allergy was introduced in year 1906 by Viennese pediatrician Clemens von Pirquet after noted that some of patients were hypersensitive to innocuous normally entities such as pollen, dust, or certain foods. Aside from ambient allergens, reactions can result foods, reactions to medications and insect strings like aspiring and antibiotics such as usage of penicillin.

Symptom of food allergy includes abdominal pain, vomiting, bloating, and diarrhea, swelling and itchy of skin during hives.

Depending of rate of severity can cause cutaneous reaction, edema, brochoconstriction, coma, hypotension and even death. While this type of reaction can also be triggered suddenly, or onset can also be delayed, severity of this type allergic response requires injections of epinephrine, through derive known as EpiPen auto-injector.

Some Risk factors for allergy can also be placed in general categories, environmental factors and namely host. The host factors include sex, heredity, age and sex with heredity being by far most significant. There have been recent increases in incidence of allergic disorders it can not be explained by some genetic factors alone. Allergic diseases are familial strongly; it is identical twins are likely to have same allergic diseases about 70 percent of time and same allergy occurs about 40 percent.