Sicherer SH, Mu|$$|Atnoz-Furlong A, Sampson HA. J Allergy Clin Immunol. 2003;112:1203–1207
Purpose of the Study.
To determine the prevalence of self-reported peanut and tree-nut allergy among the general population of the United States in 2002 and compare it with prevalence rates obtained 5 years earlier.
A total of 4855 households representing a census of 13 493 participated.
A nationwide, cross-sectional survey was administered by telephone to persons called by a random sampling of telephone numbers in the continental United States. Adults acted as surrogates for minors with peanut or tree-nut allergy. Differences in responses between groups were tested by χ2 analysis.
Fifty-three percent of contacted homes participated. Peanut allergy, tree-nut allergy, or both was self-reported in 166 (1.2%; 95% confidence interval [CI]: 1.0%, 1.4%) individuals in 155 (3.2%; 95% CI: 2.7%, 3.7%) households. These prevalence rates were similar to those reported in 1997. Any differences in prevalence rates between people of different race/ethnicity did not reach statistical significance. There was an overall male predominance of peanut or tree-nut allergy in children (P = .02) and a female predominance in adults (P = .0008). The prevalence of reported peanut allergy among children increased significantly from 0.4% in 1997 to 0.8% in 2002 (P = .05), but the rate of tree-nut allergy did not change significantly. The prevalence of peanut and tree-nut allergy in adults did not change significantly between 1997 and 2002. Overall, the adjusted prevalence rate taking into account individuals with reported allergy without convincing histories was 1.04% (95% CI: 0.9%, 1.2%). Of the reported reactions, 79% involved either respiratory symptoms or multiple organ systems. Only 74% of children and 44% of adults were evaluated by a physician for their allergic reactions, and self-injectable epinephrine was prescribed for 46% of the children and 23% of the adults.
The authors reported similar overall rates of peanut and tree-nut allergy in the United States, as was noted in 1997, but over this 5-year period the prevalence of peanut allergy in children doubled.
The findings of increased prevalence of peanut allergy may be expected with the well-documented increase of atopic diseases in the past decades. Why the prevalence of tree-nut allergy would be unchanged during this same period will require additional investigation. A notable finding in this study is that >25% of children and 50% of adults who reported peanut or tree-nut allergy did not seek medical evaluation. Even more remarkable is that after medical evaluation for peanut or tree-nut allergy, self-injectable epinephrine was prescribed to approximately half of the children and less than one quarter of the adults. This underscores the need for continued improvement in the care of patients with food allergy, which is increasing in prevalence.