Nasal allergies refer to the interaction of allergens with cells within the lining of the nose.

What is going on in the body?

Allergens enter through the nose. Allergens include pollens, dust, dust mites, mold spores, and animal dander. These substances interact with IgE antibody on the mast cells inside the nose. This causes discharge of histamine. Histamine causes sneezing, nasal congestion, and nasal discharge.

The mast cells also release other substances. These substances pull a group of cells, called eosinophils, into the nasal lining. The eosinophils travel into the lining of the nose over a 6- to 24-hour period. They then release substances that can create additional symptoms hours after the original exposure.

The first reaction is called the early reaction. The symptoms occurring hours after the initial exposure make up the late-phase reaction.

For example, an individual who is sensitive to cats will develop an immediate allergic reaction when exposed to a cat. This initial acute attack may continue as long as the individual is exposed. Once the person leaves the environment, the symptoms subside. Later, the release of eosinophils may bring on another wave of the symptoms.

What are the causes and risks of the condition?

The main cause of nasal allergies is an interaction between cells lining the nose and allergens. Common allergens include pollens, dust, dust mites, molds, and animal dander.