Between 1973 and 1985, 114 children, aged 2 to 14 years, underwent double-blind, placebo-controlled, food challenge (DBPCFC) to peanut. Thirty-two of 46 children with symptoms produced by DBPCFC to peanut were included in this longitudinal evaluation. Contact was made with the 32 subjects 2 to 14 years after their positive DBPCFC to peanut. All 32 subjects had exhibited a positive puncture skin test to peanut at the time of the original evaluation. Sixteen subjects had experienced symptoms caused by accidental peanut ingestion in the year before contact. Eight subjects had reacted to accidental ingestion in more than 1 year but less than 5 years before contact. Eight subjects had completely avoided peanut since the original evaluation and positive DBPCFC. No subjects could be demonstrated to have "outgrown" their peanut reactivity. All subjects tested continued to have skin reactivity to a puncture skin test with peanut extract. It appears uncommon for peanut-sensitive patients to lose their clinical reactivity, even after many years have elapsed. In addition, data were collected concerning reactions to other legumes and other (nonlegume) nuts. Only two patients with DBPCFC to peanut reacted on DBPCFC to soy or pea (one each). None of the subjects with a positive DBPCFC to peanut reacted to nonlegume nuts.