Description

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We refer to an immune system response to a substance that is normally not harmful to the body as an allergy. These harmful invaders are referred to as allergens. Common examples include certain foods, pollen, and animal dander.
Your immune system defends you against pathogenic microbes. To accomplish this, it attacks anything it determines to be a danger to your physical security. Allergens can cause inflammation, sneezing, and other symptoms.

Your immune system typically adapts its response to the external environment. For instance, one's immune system ought to be able to distinguish between safe substances like pet dander. When a person has a dander allergy, their immune system reacts to the allergen as though it were a dangerous foreign invader.