Question

Allergy involves:

• A. IgA
• B. IgE
• C. IgM
• D. IgG

Hint:

Remember: Allergy → IgE → Histamine release.

Answer 1

The Correct Option is B

Concept: Allergy is a hypersensitive immune response to harmless substances (allergens), mediated mainly by Immunoglobulin E (IgE).
Step 1: Role of IgE.
IgE antibodies bind to allergens and trigger the release of histamine and other chemicals from mast cells and basophils.
Step 2: Result of IgE action.
This leads to symptoms such as sneezing, itching, swelling, and inflammation.
Step 3: Evaluating the options.

• IgA $\rightarrow$ Mucosal immunity (incorrect)
• IgE $\rightarrow$ Allergy and hypersensitivity (correct)
• IgM $\rightarrow$ First antibody in primary response (incorrect)
• IgG $\rightarrow$ Long-term immunity (incorrect)

Step 4: Conclusion.
Thus, allergy involves IgE.