Mixed-up Nuts: Identification of Peanuts and Tree Nuts by Children
Authors: Lester Mitchell R. 
Published: November 2007

Ferdman RM, Church JA. Ann Allergy Asthma Immunol. 2006;97:73–77

PURPOSE OF THE STUDY. To determine the age at which nut-allergic and nonallergic children can accurately identify various nuts.

STUDY POPULATION. Thirty-seven children who were allergic to peanut or tree nuts (TNs) and 63 nonallergic children.

METHODS. A “nut box” was constructed with peanuts (shelled and unshelled) and 9 different TNs fastened to its base in separate compartments. The box was covered with a clear top for easy viewing and to prevent accidental exposure. Children were asked to identify any peanuts they saw in the box. They then were asked to identify each TN in the box. Children were asked to identify which nuts they could not eat.

RESULTS. Twenty-three children were allergic only to peanut, 5 were allergic to peanut and at least 1 TN, 5 were allergic to all TNs and peanut, 3 were allergic to ≤2 TNs, and 1 was allergic to ≥3 TNs. On average, children identified 2.7 nuts, with no difference between allergic and nonallergic children. Among allergic and nonallergic children, older children identified more nuts correctly. There was a better correlation of age with number of nuts identified correctly in the allergic (r = 0.82) than in the nonallergic (r = 0.52) group (P &lt; .001 for each group). Ten children (9 &lt;5 years old) did not identify any nuts correctly. Twenty-eight children identified only peanut in the shell. An additional 21 children identified only 2 nuts correctly, 13 of whom only identified shelled and unshelled peanut. Eighty-nine percent of those who correctly identified a nut recognized peanut in the shell, and 52% recognized shelled peanut. Although there were few differences between allergic and nonallergic children, the allergic children were less likely to recognize peanut either in the shell (81.1% vs 93.7%; P = .052) or shelled (29.7% vs 65.1%; P &lt; .001). Of the 37 allergic children, 12 (32%) correctly identified the nut(s) to which they were allergic. Another 15 children (41%) said they would eat none of the nuts, and 10 (27%) indicated that they would eat ≥1 nut to which they were allergic.

CONCLUSIONS. Peanut- and TN-allergic children can identify few nuts, which places them at increased risk of accidental ingestion of a food to which they are allergic. Avoidance and correct identification of the nuts to which a child is allergic should be part of an overall educational plan.

REVIEWER COMMENTS. Most allergists instruct strict avoidance of all TNs to their sensitive patients to decrease the risk of accidental ingestion of the offending nuts(s). Because of the high rate of TN sensitization in peanut-allergic patients and vice versa, many also recommend avoidance of TNs and peanut in both groups. Considering the high rate of misidentification of peanut and TNs in this study, that advice seems prudent. Furthermore, nuts are frequently present in small pieces in baked products, etc, and cannot easily be identified. Most patients are satisfied with the safety of complete avoidance. If a patient is intent on eating TNs to which he or she is not known to be sensitive, I recommend waiting until he or she is mature enough to correctly identify TNs proven to be safe by a thorough allergy evaluation. Even then, I recommend eating the “safe” TN from the shell.