This fact is from Allergy & Anaphylaxis in General Medicine. It is a commonly tested concept in NEET MDS examinations. Understanding this fact is crucial for answering MCQs correctly.
Type I = immediate IgE mediated = anaphylaxis
Type II = cytotoxic IgG IgM = hemolytic reactions
Type III = immune complex = Arthus serum sickness
Type IV = delayed T-cell mediated = contact dermatitis TB test
First drug anaphylaxis = Epinephrine 0.3-0.5mg IM anterolateral thigh.