Anaphylaxis Overview and Grading

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Questions and Answers

What is the main treatment approach when refractory anaphylaxis is present?

Increased doses of oral vasodilators

Repeated doses of adrenaline with broncho-dilators (correct)

Administering oral antihistamines

Immediate surgical intervention

How does low-dose adrenaline primarily function in treating anaphylaxis?

By increasing vascular permeability

By directly blocking histamine receptors

By enhancing cardiac contractility and rate to support blood pressure (correct)

By causing potent vasodilation

What role do mast cells play during an allergic reaction?

Directly neutralizing IgE antibodies

Releasing epinephrine into the bloodstream

Degranulating to release chemicals including histamine (correct)

Producing platelet-activating factor

Which chemical is specifically involved in increasing vascular permeability during an immune response?

Platelet-activating factor (PAF) Signup and view all the answers

What primarily methods of action does adrenaline possess at higher doses?

Both alpha and beta receptor effects Signup and view all the answers

What is the primary characteristic of anaphylaxis?

It is a life-threatening hypersensitivity reaction. Signup and view all the answers

Which of the following symptoms best describes objective dyspnoea?

Gasping with increased respiratory rate. Signup and view all the answers

Which grade of anaphylaxis represents a local reaction on the skin without changing vital signs?

Grade 1 Signup and view all the answers

What distinguishes Grade 3 (b) from Grade 3 (a) in anaphylaxis?

Grade 3 (b) involves severe cardiovascular issues. Signup and view all the answers

How are food intolerances characterized compared to allergies?

Intolerances involve delayed reactions and are not life-threatening. Signup and view all the answers

What triggers the production of an inappropriate immune response in allergic reactions?

Exposure to allergens. Signup and view all the answers

What does the term 'angioedema' refer to?

Localized swelling under the skin surface. Signup and view all the answers

Which of the following best describes anaphylaxis in terms of its effects?

It can have either generalized or systemic effects. Signup and view all the answers

What type of antibodies do B-lymphocytes produce upon initial exposure to an allergen?

Immunoglobulin E (IgE) Signup and view all the answers

Which immune cells first bind to immunoglobulin E (IgE) during an allergic reaction?

Mast cells Signup and view all the answers

What is a major effect of histamine release during an allergic reaction?

Increased vascular permeability Signup and view all the answers

What is the role of platelet-activating factor (PAF) during anaphylaxis?

Break down endothelial cells Signup and view all the answers

What effect does bronchoconstriction have on the airway during an allergic reaction?

Narrowing of air passageways Signup and view all the answers

What is the result of vasodilation during an allergic reaction?

Drop in blood pressure Signup and view all the answers

What chemical is released from mast cells and contributes to bronchoconstriction?

Histamine Signup and view all the answers

What happens to IgE during the later stages of an allergic reaction?

IgE binds to basophils Signup and view all the answers

Study Notes

Anaphylaxis

Life-threatening allergic reaction affecting airway, breathing, and circulation, often accompanied by skin symptoms.
A generalised or systemic hypersensitivity reaction.
Some individuals are more susceptible due to genetics or environmental factors.

Slide 4 (Meanings of Words)

Urticaria (hives): Red, itchy bumps with rash.
Angioedema: Swelling under the skin's surface.
Objective Dyspnea: Gasping, increased respiratory rate, and decreased oxygen saturation, requiring accessory muscles.

Grading of Anaphylaxis

Grade 1 (Local Reaction): Skin reactions only, no changes in vital signs.
Grade 2 (Mild/Moderate): Skin and gastrointestinal tract (GIT) involvement, like vomiting and diarrhea.
- Grade 2a: Similar to Grade 2b.
Grade 3 (Severe): Respiratory or cardiovascular involvement (e.g., blood pressure/heart rate changes).
- Grade 3a: Similar to Grade 3b.
Grade 3C (SEVERE): Respiratory arrest and/or cardiovascular arrest.

Intolerances and Allergies

Intolerance and allergy are often used interchangeably.
Intolerance is an adverse reaction to substances (e.g., food groups, lactose, gluten).
Reactions to intolerances are often delayed, occurring several hours to days after ingestion and are not life-threatening.
Reactions to allergens appear quickly after exposure.

Pathophysiology of Anaphylaxis

Exposure to allergen: Person is exposed to the allergen, sometimes the reaction mirrors the method of introduction (e.g., inhaled allergen causing respiratory issues).
B-lymphocytes and IgE: Upon initial exposure, B-lymphocytes produce antibodies, immunoglobulin E (IgE).
Mast cells and basophils: IgE binds to mast cells and basophils, which are involved in protecting from harmful allergens.
Allergen re-exposure: Subsequent exposure to the same allergen leads to raised IgE levels.
Chemical mediators: Mast cells release chemical mediators (e.g., histamine).
Systemic effects: Massive histamine release leads to various systemic effects, such as vasodilation (rapid drop in blood pressure).
Vasodilation: Reduced blood pressure also means blood with allergen is closer to the skin.
Bronchoconstriction: Histamine binding to receptors in the bronchioles results in bronchoconstriction and increased mucus production.

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Description

This quiz explores the life-threatening effects of anaphylaxis, including symptoms and grading criteria. It covers essential medical terminologies associated with allergic reactions and the physiological impacts on the body. Test your understanding of the classifications and definitions related to anaphylaxis.