Diagnosing peanut allergy with skin prick and specific IgE testing

J Allergy Clin Immunol. 2005 Jun;115(6):1291-6. doi: 10.1016/j.jaci.2005.02.038.


Background: Food allergy is common in childhood. It has been suggested that the magnitude of a skin prick test or specific IgE result can improve diagnostic usefulness, but this has been addressed in only a few tertiary challenge-based studies.

Objective: To determine the predictive value of a wheal > or = 8 mm or serum specific IgE > or = 15 kU A /L for clinical allergy and investigate whether results are generalizable.

Methods: All subjects, up to 16 years of age, who had been investigated with a peanut or tree nut food challenge were eligible for the study. Subjects were referred from either a tertiary allergy clinic or a community birth cohort. All subjects with a history suggestive of food allergy were offered a challenge unless there were features of anaphylaxis. Details of challenges were prospectively recorded. Results were modeled by using logistic regression.

Results: There was a total of 161 peanut challenges. Recent skin prick (longest wheal diameter) and specific IgE data were available for 135 and 136 challenges, respectively. The results suggest that a skin prick result > or = 8 mm and a specific IgE > or = 15 kU A /L have predictive values of 95% (95% CI, 76.2% to 99.9%) and 92.0% (74.0% to 99.0%), respectively, for a positive challenge. Age, the type of nut, and referral pattern of the subject did not appear to alter this relationship.

Conclusion: These data suggest that a skin prick result > or = 8 mm or a specific IgE > or = 15 kU A /L have a high predictive value for clinical allergy to peanut and that these cutoff figures appear generalizable to different populations of children undergoing an assessment for peanut allergy.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Allergens* / adverse effects
  • Antibody Specificity
  • Antigens, Plant
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Immunoglobulin E / blood*
  • Infant
  • Male
  • Peanut Hypersensitivity / blood
  • Peanut Hypersensitivity / diagnosis*
  • Peanut Hypersensitivity / etiology
  • Predictive Value of Tests
  • Skin Tests
  • United Kingdom


  • Allergens
  • Ana o 2 allergen, cashew
  • Antigens, Plant
  • Immunoglobulin E