Concordance of different sources for nickel sulphate patch testing

Abstract

INTRODUCTION Nickel is the most frequent cause of contact allergy worlwide and it still remains a public health problem.1 In our department, we use as patch testing technique Curatest® (Lohmann & Rauscher International GmbH & Co.KG, Rengsdorf, Germany) and two supports of allergens interchangeably: Chemotechnique® (Chemotechnique MB Diagnos tics AB, Vellinge, Sweden) and AllergEAZE® (Smartpractice, Calgary, Canada). Both commercial patch test substances have a marketing authorization in Spain. We observed that some patients with signs suggestive of nickel-allergic contact dermatitis (ACD) had negative tests, so we suspected that the supplier used could influence the out come. For this reason, we decided to carry out a study to determine the degree of concordance between two different commercial sources, measured with Cohen's kappa coefficient.