When your body responds to an allergy, it has to work very hard and diligently to repair itself. The first time your body comes across an allergen, your plasma cells release immunoglobin E, otherwise known as Ige, which is an antibody that represents that specific allergen. The body will produce an immune response because it perceives these substances as an immediate threat.
Our immune cells are always seeking out dangers such as parasites, toxic substances, bacteria, and viruses. When these molecules enter the body through the intestine, mouth, and lungs, or the skin, they are labeled as being dangerous or harmful, as the immune system reacts to these properties. If the immune response to it as being a threat, a pro-inflammatory response occurs as a result. This result is what is called a Type 2 immune response, and a different class of T-cells appears.