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.