Atopy patch testing for foods: a review of the literature.

The atopy patch test (APT) was first reported in 1895 by the German dermatologist, Jadassohn and was used for evaluation of contact dermatitis. The first documented epicutaneous application of aeroallergens was by Rostenberg and Sulzbergen in 1937. Although others including Mitchell and Platts-Mills, further described patch testing with aeroallergens, Langeland et al. initially described the use of patch testing with foods by testing atopic patients against egg white. Subsequently, food patch testing has gained popularity and has been included as a potential test to assess for food allergy not only for atopic dermatitis (AD) but also eosinophilic esophagitis and food protein-induced enterocolitis syndrome, although its role still remains unclear. Through a comprehensive literature review, this article addresses the use of APT for foods and its application in AD and other allergic diseases. There will be inclusion of some data from aeroallergen and hapten patch testing as a basis from which our knowledge for food APT is derived. The data, in particular the sensitivity, specificity, and predictive values, vary widely from 0 to 100%, depending on the study. Given this large variation in test results, food APT use in isolation is not recommended at this time. Additional studies are needed to standardize, improve accuracy and reproducibility, and determine its role in the evaluation of allergic diseases.