This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Which of the following findings provides the best evidence of insect sting hypersensitivity? 
Select and explain. 
A. Positive prick or intradermal skin test, B. Extensive local reaction lasting 5-7 days, C. Documented evidence of a systemic allergic reaction, D. Specific antivenom IgE antibodies
C: Documented evidence of a systemic allergic reaction
Answer: C: Documented evidence of a systemic allergic reaction 
Explanation: Clinical documentation of a systemic allergic reaction is essential to the accurate diagnosis of insect sting hypersensitivity. Typically, signs of anaphylaxis develop within minutes after the sting. Subsequent prick or intradermal skin testing, supplemented as necessary by antivenom IgE levels (determined by radioallergosorbent test ), provide confirming evidence of hypersensitivity. A large local reaction alone, whether of sho or prolonged duration, does not provide sufficient evidence of IgE-mediated hypersensitivity. Antivenom IgG levels are used to cha the response to immunotherapy.