Stages of an Allergic Reaction
An allergic reaction is a response of the immune system to a foreign substance, called an allergen. An allergic reaction typically occurs in four stages:
Stage 1: Prodrome
This is the initial period of contact with the allergen, lasting up to an hour. During this period, the body recognizes the allergen as an unwelcome invader and begins to produce antibodies against it. Symptoms may include itching and redness.
Stage 2: Acute Reaction
This period lasts anywhere from a few minutes to several hours. During this stage, the antibodies produced in stage one act on the allergen, causing inflammation and the release of histamines. Symptoms may include hives, swelling, and difficulty breathing.
Stage 3: Resolution
The body begins to break down the allergen, which usually leads to a reduction in symptoms. This stage may last several hours.
Stage 4: Recovery
This is the period after the allergen has been broken down and the symptoms have subsided. This stage is the recovery period, and symptoms may persist for several days.