The four types of hypersensitivity explained (Gell and Coombs classification): Type I (allergy), Type II (cytotoxic), Type III (immune complex), and Type IV (delayed). Mechanisms,...
Allergy vs autoimmunity compared clearly: both are immune reactions against the wrong target, but allergy attacks a harmless foreign substance while autoimmunity attacks the body's...
Type III hypersensitivity explained by mechanism: why the antigen-antibody ratio decides everything, why small complexes at antigen excess are the dangerous ones, and how immune co...
Type IV (delayed-type) hypersensitivity explained by mechanism: why it is the only hypersensitivity with no antibodies, why the reaction takes 48 to 72 hours, and how T cells and m...
Type II hypersensitivity explained by mechanism: the three ways an antibody bound to a cell causes damage, why Graves disease and myasthenia gravis sit at opposite ends of the same...
Type I hypersensitivity explained through its mechanism: why the first allergen exposure is silent, why the second fires in minutes, and how to tell the immediate reaction from the...
MCQ Immunology (56-70): Hypersensitivity Answers with Explanations
