LACK OF REPRODUCIBILITY OF A SINGLE NEGATIVE STING CHALLENGE RESPONSEIN THE ASSESSMENT OF ANAPHYLACTIC RISK IN PATIENTS WITH SUSPECTED YELLOW JACKET HYPERSENSITIVITY

To investigate the reproducibility of a single negative response to st ing challenge with a living insect, we rechallenged a group of 61 pati ents who showed no clinical response to a first sting challenge. All p atients had previously had symptoms suggestive of anaphylaxis after a yellow jacket field sting. Thirteen patients (21%) had anaphylactic re sponses after the second sting challenge, and sh of these patients had severe reactions including symptomatic hypotension requiring administ ration of Adrenalin. This rate was significantly lower than the respon se rate of the original patient group to a first sting challenge (39%) . Thus although fewer positive responses were observed in patients who had had a previous negative challenge response, the number of anaphyl actic reactions was considerable and included patients with potentiall y life-threatening symptoms. Consequently, a single sting challenge ma y not be used to select patients for venom immunotherapy.