Summary
Four types, I to IV, describe immediate IgE reactions, cytotoxic, immune complex and delayed T cell responses.
In depth
Type I: IgE-mediated (allergy). Type II: antibody against cell surface (transfusion reaction). Type III: immune complexes (serum sickness, lupus). Type IV: T cell-mediated, delayed (contact dermatitis, tuberculin test).
Gell and Coombs classification. Type I is immediate, within minutes; type IV takes 48 to 72 hours. Treatment depends on type: adrenaline, steroids, avoidance.
Remember: the tuberculin skin test is type IV.
Frequently asked questions
What is Hypersensitivity Types?
Four types, I to IV, describe immediate IgE reactions, cytotoxic, immune complex and delayed T cell responses.
Which area of biology covers Hypersensitivity Types, and how advanced is it?
Hypersensitivity Types is one of the 52 topics in Immunology & Disease. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Blood Groups and Transfusion, Antigens, Adaptive Immunity.
Can you give an example of Hypersensitivity Types?
Poison ivy rash is type IV.
What should I learn before Hypersensitivity Types?
Work through the Beginner topics in Immunology & Disease first, such as Immune System, Viruses, Innate Immunity, then return to Hypersensitivity Types. Advanced topics assume the Intermediate vocabulary.
What topics are related to Hypersensitivity Types?
The closest topics to Hypersensitivity Types are Blood Groups and Transfusion, Antigens, Adaptive Immunity, Immune System. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Hypersensitivity Types?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Hypersensitivity Types. To practise the whole of Immunology & Disease, use the Immunology & Disease quiz.
How is Hypersensitivity Types different from Blood Groups and Transfusion?
Hypersensitivity Types: Four types, I to IV, describe immediate IgE reactions, cytotoxic, immune complex and delayed T cell responses. Blood Groups and Transfusion: ABO and Rh antigens on red cells determine compatible donors, since mismatches trigger agglutination. Read both side by side and note what each one explains.
How should I study Hypersensitivity Types step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Blood Groups and Transfusion and explain the difference aloud. Finally, take the Immunology & Disease quiz and come back to this page for any question you miss.