Anaphylaxis to piñon nuts.

A 21-year-old white male developed life threatening systemic anaphylaxis within seconds of ingesting a small amount of a cookie containing piñon nuts. Skin testing, ELISA, and basophil histamine release studies demonstrated piñon nut-specific IgE. Electrophoresis of the piñon nut extract demonstrated 30 bands, three of which (in the 66 to 68,000 dalton range) bound IgE in the patient's serum in an immunoblot. Ingestion challenge was not performed due to the severity of the patient's reaction. Although used for centuries in certain cultures, piñon nuts are now being eaten more frequently in the American diet. Physicians should be aware of the potential for anaphylactic reactions following ingestion of this food.