Question

The severity of an allergic reaction is often related to the:

A. Age of the patient
B. Previous history of reactions
C. Antigen
D. Speed of onset

Answer 1

The severity of an allergic reaction is most influenced by an individual's past history of reactions. Previous allergic episodes significantly impact the intensity of subsequent reactions to allergens.

B. Previous history of reactions

Step-by-step explanation:

The severity of an allergic reaction is often most closely related to the previous history of reactions experienced by an individual. Individuals who have had severe allergic reactions in the past are more likely to have intense reactions in subsequent exposures to the allergen. This is due to the body's heightened sensitivity and increased immune response triggered by prior exposures, leading to a more severe reaction.(B)

The relationship between previous reactions and the severity of an allergic reaction can be explained through immunological memory. Upon initial exposure to an allergen, the body produces specific antibodies (IgE) and sensitizes immune cells. Upon subsequent exposure, these sensitized cells trigger a rapid and amplified release of histamine and other chemicals, leading to a more severe reaction. This process, known as sensitization, amplifies the allergic response and escalates the reaction's severity.

Moreover, individuals with a history of severe allergic reactions tend to be prescribed auto-injectable epinephrine (such as EpiPen) as a precautionary measure. The prompt administration of epinephrine can counteract the severe symptoms by relaxing the airway muscles and increasing blood flow to help alleviate the potentially life-threatening effects of a severe allergic reaction. Therefore, understanding an individual's previous allergic history is crucial in predicting and managing the severity of allergic reactions.

Answer 2

The severity of an allergic reaction is often related to the individual's previous history of reactions (B). Type I Hypersensitivities involve a rapid immune response that can escalate with each exposure to an allergen, like pollen, which can cause reactions like sneezing or anaphylactic shock.

Thus option B. Previous history of reactions. is correct answer.

Step-by-step explanation:

Allergic Reactions and Their Severity

The severity of an allergic reaction can depend on several factors, but according to the options provided, it is closely related to the B. previous history of reactions. Allergic reactions, specifically Type I Hypersensitivities, involve a rapid immune response upon re-exposure to an allergen, which could range from mild to life-threatening symptoms.

The previous exposure to the allergen results in the production of IgE antibodies, which sensitize the individual. Upon subsequent exposures, these antibodies react to the allergen and trigger mast cells to release histamines, leading to the symptoms of an allergic reaction.

An extreme reaction, anaphylactic shock, is life-threatening and requires immediate treatment with epinephrine followed by antihistamines and potentially corticosteroids.

Immediate hypersensitivity reactions are often rapid, as the name suggests, and include symptoms like sneezing, itchy eyes, and more severe responses like anaphylaxis. Pollen allergy is an example of an immediate hypersensitivity reaction, not an autoimmune, immunodeficiency, or delayed hypersensitivity reaction.

Thus option B. Previous history of reactions. is correct answer.