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Allergic rhinitis
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Allergic rhinitis is an allergy that happens inside the nose. The person gets congested, clear fluid runs from the nose, they sneeze and their nose itches.
Behind that there is an antibody, immunoglobulin E, a defense protein that can recognize one specific substance. When the allergen, the substance that sets off the allergy, comes in with the air you breathe, that immunoglobulin E drives the response and the mast cell, a cell in the lining of the nose, degranulates: it opens its granules and releases histamine all at once. The mast cell already has the histamine packaged, and the inhaled allergen simply opens the package.
Every symptom comes from there. Histamine acts on the trigeminal nerve, the nerve that carries sensation from the face, and that is where the sneezing comes from; it also stimulates the glands in the lining, which make more fluid, and that is the runny nose. Other substances released in the same reaction, leukotrienes and prostaglandins, act on the blood vessels of the nose, and they are the ones that cause the congestion.
In brief
Allergic rhinitis is an atopic disease with nasal congestion, clear rhinorrhea, sneezing, postnasal drip and nasal itching.
Its early phase is an immunoglobulin E mediated response to inhaled allergens that degranulates the mast cell and releases histamine.
The mast cell already has the histamine packaged, and the inhaled allergen simply opens the package.
Histamine triggers sneezing through the trigeminal nerve and rhinorrhea by stimulating the mucous glands; leukotrienes and prostaglandins act on the blood vessels and cause congestion.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingAllergic Rhinitis, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated