What does a skin prick test assess?

What does a skin prick test assess?

• A. Total IgE levels
• B. Allergen-specific IgE-mediated response
• C. Complement levels
• D. RBC agglutination

Answer: (B)

Skin prick testing measures allergen-specific IgE–mediated responses. When a suspected allergen is pricked into the skin, if specific IgE on cutaneous mast cells recognizes it, the IgE cross-links and triggers degranulation, releasing mediators like histamine. This causes a localized wheal-and-flare reaction within about 15–20 minutes, indicating sensitization to that allergen. It reflects the presence of allergen-specific IgE on skin mast cells, not the overall (total) IgE level in blood. It also does not assess complement levels or red blood cell agglutination, which involve different immune mechanisms.

Skin prick testing measures allergen-specific IgE–mediated responses. When a suspected allergen is pricked into the skin, if specific IgE on cutaneous mast cells recognizes it, the IgE cross-links and triggers degranulation, releasing mediators like histamine. This causes a localized wheal-and-flare reaction within about 15–20 minutes, indicating sensitization to that allergen. It reflects the presence of allergen-specific IgE on skin mast cells, not the overall (total) IgE level in blood. It also does not assess complement levels or red blood cell agglutination, which involve different immune mechanisms.