Intraoperative anaphylaxis: an association with latex sensitivity. Latex products have recently been identified as the cause of severe intraoperative anaphylactic reactions. We have identified a group of pediatric patients who appear to be at increased risk for such reactions. Fifteen patients with either spina bifida or congenital urologic abnormalities experienced 19 intraoperative anaphylactic reactions. All patients had frequent previous exposures to rubber materials since infancy as part of their management and/or investigative procedures. Seven of 15 patients had a previous history of local skin reactions to rubber. Only four patients were atopic. All patients had undergone multiple (two of 26) operative procedures before their reactions, the onset of which ranged from 40 to 290 minutes after induction of anesthesia. The reactions varied in intensity from urticaria to severe cardiorespiratory collapse. All these patients subsequently had positive allergy skin tests and positive RAST to latex antigen. We conclude that this group is at risk when they are exposed to latex intraoperatively as a result of frequent past exposure to these materials. Allergic evaluation for latex allergy may assist in the preoperative evaluation of similar patients. In sensitized patients, appropriate prophylactic measures, particularly the avoidance of latex, is required. 