What follows the early reaction in allergic rhinitis, usually occurring within six hours?

In allergic rhinitis, the early phase of the allergic reaction is characterized by immediate hypersensitivity, which occurs within minutes of exposure to the allergen. This includes the release of various mediators from mast cells, such as histamine, leading to symptoms such as sneezing, itching, and nasal congestion.

The correct response refers to what follows this immediate phase. After the early reaction, usually occurring within six hours, a delayed inflammatory response takes place. This involves the recruitment of additional immune cells, including eosinophils and T cells, to the site of the allergen exposure. This secondary response contributes to the chronic symptoms associated with allergic rhinitis and can take several hours to develop, sometimes leading to worsening of symptoms after the immediate phase has subsided.

This progression from immediate hypersensitivity to a delayed inflammatory response is central to understanding the pathophysiology of allergic reactions and highlights the involvement of different immune mechanisms over time.