Allergies can be explained as abnormal reaction by an individual’s immune system against a substance, which is normally harmless. An allergy attack occurs when the allergen binds with the allergic antibodies located on the allergic cells (basophils, mast cells etc) of a person’s body. The binding results in secretion of chemicals like leukotrienes and histamine. Slowly, the affected person starts experiencing several allergic symptoms. Allergy attacks may occur during any phase of life, but it’s more common in children and teenagers.

The most common allergens include: medications, molds, pollens, dust mites, animal dander, foods and venoms. These substances affect human immune system though a procedure known as sensitization. Sensitization is the point when an individual’s immune system gets exposed to enough quantity of allergens that is required by the body to produce allergic antibodies.

Once sensitization is carried out properly, the person will suffer from allergic symptoms whenever he or she comes in contact with the allergen in future. These symptoms vary depending on the variety of allergens.

It’s also a fact that not all people are allergic to the same substance. The reason behind this is still unknown. Gene may play a major role in this. It has been seen that sometimes the same kind of allergens affects the entire family.