This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
Contrast agent-induced reactions like edema, uicaria, rash, and hypotension are mediated due to 
Select and explain. 
A. IgG mediated reaction, B. Anaphylactoid reaction, C. Type I allergic reaction, D. IgE mediated reaction
B: Anaphylactoid reaction
Answer: B: Anaphylactoid reaction 
Explanation: Anaphylactoid reactions are defined as those reactions that produce the same clinical picture with anaphylaxis but are not IgE mediated, occur through a direct nonimmune-mediated release of mediators from mast cells and/or basophils or result from direct complement activation. More common in iodinated contrast media Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 163-165