Mehl A, Rolinck-Werninghaus C, Staden U, et al. J Allergy Clin Immunol. 2006;118:923–929
PURPOSE OF THE STUDY. To determine the utility of atopy patch tests (APTs) in the diagnostic evaluation of food allergy.
STUDY POPULATION. A cohort of 437 children (median age: 13 months; 90% with atopic dermatitis) who were referred for evaluation of suspected food allergy.
METHODS. Specific serum immunoglobulin E (sIgE) measurements, skin-prick tests (SPTs), APTs, and controlled oral food challenges were performed.
RESULTS. The outcomes of 873 oral challenges with cow's milk, hen's egg, wheat, and/or soy were analyzed. One thousand seven hundred single APTs were performed. As a single parameter, the APTs showed the best specificity compared with sIgE measurements, SPTs, or both. Combining the APT with either the SPT or sIgE measurement resulted in improved sensitivity and specificity. Decision points for sIgE measurement and for the SPT showed lower values when combined with a positive APT result. By including the APT in the evaluation, only between 0.5% and 7.0% (99% predicted probability) and between 6% and 14% (using 95% predicted probability) of children would fulfill the criteria for avoiding an oral food challenge.
CONCLUSIONS. Although the predictive capacity of the APT is improved when combined with sIgE measurement or the SPT, oral food challenges become superfluous in only 0.5% to 14.0% of study patients. In addition, the APT is time-consuming and demands a highly experienced test evaluator. For daily clinical practice, the APT adds only a small predictive value to the standard SPT and sIgE measurement in the diagnostic workup of suspected food-related symptoms in children with atopic dermatitis.
REVIEWER COMMENTS. The APT is presumed to reflect late-phase clinical reactions. However, even with late onset of symptoms (>2 hours after food ingestion), the performance of the APT was not consistent in the children with atopic dermatitis. The question that remains unanswered is whether the APT could be used to diagnose non–IgE-mediated gastrointestinal reactions to foods, such as allergic eosinophilic esophagitis/gastroenteritis or food protein–induced enterocolitis syndrome.
- Copyright © 2007 by the American Academy of Pediatrics