There are three main causes of allergy symptoms: allergic rhinitis, irritant rhinitis or a combination of both (called mixed rhinitis). Allergic rhinitis is caused by a component of your immune system called the immunoglobin E (IgE) antibody. If you have allergic rhinitis, triggers like seasonal pollen, pets, dust mites, or even cockroaches cause the IgE immune system to react just like your immune system would react against a virus or bacteria.
Irritant rhinitis, or nonallergic rhinitis, is a direct irritation of your nose. In this case, something bothers the inside surface of the nose and causes allergy symptoms. Sometimes there is a local “dumb” or innate immune response as the cause of allergy symptoms. And sometimes it is a nerve response that causes the irritant allergy symptoms. But in each case, the cause of nonallergic rhinitis is not the full immune response seen as the cause of allergic rhinitis, but a more local response.