Raj. CHO - 2023: Severe type of hypersensitivity can cause.

Raj. CHO - 2023

Applied Microbiology & Infection control

Easy

Appeared in: Raj. CHO - 2023

Explanation

A severe, systemic Type I hypersensitivity reaction is also known as anaphylaxis.
Anaphylaxis involves the massive release of inflammatory mediators like histamine from mast cells and basophils upon exposure to an allergen.
This massive release of mediators causes widespread vasodilation, increased vascular permeability, and bronchoconstriction, leading to a form of distributive shock called anaphylactic shock.

Option A: Septic shock is caused by a dysregulated host response to a severe infection (sepsis), not by a hypersensitivity reaction.
Option C: Obstructive shock is caused by a physical blockage of blood flow to or from the heart, such as a pulmonary embolism or cardiac tamponade.
Option D: Neurogenic shock results from a loss of sympathetic nervous system tone, which leads to vasodilation. It is not caused by an allergic or hypersensitivity mechanism.

Visual 1: Flowchart: Pathophysiology of Anaphylactic Shock. This visual would illustrate the sequence from allergen exposure to IgE activation, mast cell degranulation, histamine release, and the resulting systemic effects (vasodilation, bronchoconstriction, edema) leading to shock.
Visual 2: Table: Comparison of Shock Types. A table comparing Anaphylactic, Septic, Obstructive, and Neurogenic shock based on their cause, primary mechanism, and key hemodynamic changes would be highly beneficial for differentiating these critical conditions.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Relationship between hypersensitivity reactions and types of circulatory shock as background academic context rather than a clinical decision trigger.
Anaphylactic shock is a medical emergency requiring immediate recognition and intervention. The priority nursing action is the administration of intramuscular epinephrine to reverse life-threatening symptoms.
Nurses must be vigilant in monitoring patients for signs of anaphylaxis, especially when administering new medications, blood products, or contrast media.
Patient education is crucial for individuals with known severe allergies. This includes teaching them how to avoid triggers, recognize symptoms of anaphylaxis, and properly use an epinephrine auto-injector.

How to Approach the Question

First, identify the key concept in the question stem: 'severe type of hypersensitivity'.
Recall that the most severe, acute hypersensitivity reaction is Type I, which is responsible for anaphylaxis.
Next, analyze the options, which are all different classifications of shock. The goal is to match the cause (hypersensitivity) with the correct effect (a specific type of shock).
Systematically differentiate the pathophysiology of each shock type: Anaphylactic (allergic reaction), Septic (infection), Obstructive (physical blockage), and Neurogenic (nervous system damage).
Conclude that the massive, systemic release of mediators during a severe hypersensitivity reaction directly leads to the clinical syndrome of anaphylactic shock.

Concept Tested & Keywords

Concept Tested: Relationship between hypersensitivity reactions and types of circulatory shock.
Stem keywords: Severe type, hypersensitivity
Lead-in keywords: can cause