Allergic reactions occur when the body’s immune system overreacts to substances that are usually harmless. This exaggerated response can lead to a range of symptoms, from mild discomfort to life-threatening complications. In this blog post, we delve into the intricate process of allergic reactions, exploring what happens in the body during an allergic response.
Recognition of Allergens:
The first step in an allergic reaction is the recognition of allergens by the immune system. Allergens are substances like pollen, dust mites, pet dander, or certain foods that trigger the immune system’s response in allergic individuals.
Activation of Immune Cells:
Upon exposure to an allergen, the immune system’s specialised cells, known as mast cells and basophils, become activated. These cells contain granules filled with inflammatory substances, including histamine.
Release of Histamine and Other Chemicals:
Activation of mast cells and basophils leads to the release of histamine and other chemical mediators into the bloodstream. Histamine is primarily responsible for the characteristic symptoms of an allergic reaction, such as itching, swelling, and mucus production.
Inflammatory Response:
Histamine and other inflammatory substances cause blood vessels to dilate and become more permeable, allowing fluid to leak into surrounding tissues. This results in swelling, redness, and heat at the site of the allergic reaction.
Symptoms Manifestation:
The release of histamine and other chemicals triggers a cascade of symptoms throughout the body. These symptoms can vary depending on the type of allergen and the individual’s sensitivity. Common allergic symptoms include itching, hives, nasal congestion, sneezing, coughing, wheezing, and gastrointestinal disturbances.
Systemic Reactions:
In severe cases, allergic reactions can become systemic, affecting multiple organ systems and leading to a condition known as anaphylaxis. Anaphylaxis is a medical emergency characterised by a rapid onset of symptoms, including difficulty breathing, swelling of the throat and tongue, a drop in blood pressure, and loss of consciousness. Without prompt treatment, anaphylaxis can be fatal.
Resolution of the Reaction:
Once the allergen is removed or neutralised, the allergic reaction begins to subside. The body’s immune system works to clear away the inflammatory substances and repair any tissue damage caused by the reaction.
Allergic reactions are complex immune responses that involve the activation of immune cells, release of inflammatory mediators, and manifestation of various symptoms throughout the body. By understanding the mechanisms underlying allergic reactions, healthcare professionals can better diagnose, treat, and manage allergic conditions.