QuestionSBA
QuestionChoice
Mediated by IgE. These antibodies first increase when exposed to the antigen for the first time/ known as sensitisation. They attach to mast cells so that when the allergen is encountered again histamines are released by the mast cells producing signs and symptoms of allergy.

Onset within minutes.

These include allergies, and atopic diseases such as asthma, hayfever and eczema.
10005757
b
Type I
QuestionChoice
Antibody-mediated cytotoxic reaction. Antibodies are specific to a cell surface that directly bind and cause damage.

Onset can be hours to days.

This can be in autoimmune haemolytic anaemia and haemolytic disease of the newborn.
10005758
c
Type II
QuestionChoice
Antigen-antibody complexes deposit into tissues causing activation of the classical
complement system. this activates immune cells that release enzymes and free radicals that cause tissue damage.

Onset can be hours to weeks.

This can be seen in rheumatoid arthritis, post-streptococcal glomerulonephritis and serum sickness.
10005756
a
Type III
QuestionChoice
There is no type 6 hypersensitivity reaction.
10005760
e
Type VI
QuestionChoice
T- cell-mediated. When first exposed, the T cells are activated and sensitised to the antigen so that when they are exposed again there will be an inflammatory response.

Delayed hypersensitivity; typically occurs 24-48 hours after exposure to the antigen.

Local inflammation and damage are caused such as in contact dermatitis and the Mantoux test for Tuberculosis.
10005759
d
Type IV
Concept
Chapter
2693
4091
Hypersensitivity reactions
Topic
158
Immunology
13698
A 60 year old female presents to the GP suffering from pain and stiffness in her hands, wrists and knees. She has noticed more weakness and fatigue that are getting her down.

Rheumatoid arthritis is suspected and an X-ray showing typical features along with a positive anti-CCP supports this diagnosis.

She is wanting to know more about the cause of her condition. You explain it is an autoimmune condition where immune complexes deposit onto tissues causing inflammation and the symptoms she is experiencing.

What hypersensitivity reaction is this?
a