QuestionSBA
QuestionChoice
The clinical vignette describes a typical case of anaphylaxis. This is a type 1 hypersensitivity reaction in which mast-cells are activated via IgE antibody binding. When a person then encounters this antigen again, mediators such as histamine and leukotrienes are released, resulting in widespread vasodilation and bronchoconstriction. This bronchoconstriction is what gives rise to the wheeze that this patient demonstrates.
10025750
a
Type 1 hypersensitivity reaction
QuestionChoice
The clinical vignette describes a typical case of anaphylaxis, which is a type 1 hypersensitivity reaction. In type 2 sensitivity reactions antigens on the cell surface are targeted by antibodies, triggering an immune response when these antigens are presented to T-cells. An example of this would be an acute transfusion reaction.
10025751
b
Type 2 hypersensitivity reaction
QuestionChoice
The clinical vignette describes a typical case of anaphylaxis, which is a type 1 hypersensitivity reaction. Type 5 hypersensitivity reaction involves antibodies against hormone-producing cells. An example is Graves' disease.
10025754
e
Type 5 hypersensitivity reaction
QuestionChoice
The clinical vignette describes a typical case of anaphylaxis, which is a type 1 hypersensitivity reaction. Type 4 hypersensitivity reactions are mediated by T-cell activation and usually occur over days as opposed to minutes. An example is contact dermatitis.
10025753
d
Type 4 hypersensitivity reaction
QuestionChoice
The clinical vignette describes a typical case of anaphylaxis, which is a type 1 hypersensitivity reaction. Type 3 hypersensitivity reactions involve antigen-antibody complexes that may eventually damage tissues. An example is rheumatoid arthritis.
10025752
c
Type 3 hypersensitivity reaction
Concept
Chapter
2693
4446
Anaphylaxis (Paediatrics)
Topic
153
Paediatrics
17548
A 4 year old child is rushed to A&E by his worried mum after he tried a peanut for the first time and began wheezing. On the journey, he also developed an itchy rash.

On examination the child has an increased respiratory rate and wheeze. He also has widespread erythematous wheals with well-defined borders.

The doctor administers IM adrenaline which resolves the symptoms.

Which of the following types of hypersensitivity reaction has occurred?
a