[Alahan hidung ; 过敏性鼻炎] Allergy occurs when the body reacts to non-intolerable substances. Ingredients, such as pollen or dust mites, are called environmental antigens, or allergens, and are usually harmless. But a person's immune system with allergies looks at the allergen as dangerous substance. Allergic rhinitis is inflammation or irritation of the mucous membranes in the nose. Nose allergies occur when allergens, such as pollen, cause your body to defend itself by produci