Characterization of the Molecular Mechanisms Involved in Delayed-Type Hypersensitivity Reactions to House Dust Mite, Diphencyprone, Nickel, and Tuberculin Purified Protein Derivative in Healthy Volunteers

This study will be conducted in 2 cohorts. In Cohort A, approximately 40 subjects will participate in a single‐center, open‐label, non‐randomized, parallel‐group trial to investigate the molecular mechanisms involved in delayed‐type hypersensitivity (DTH) to various antigens and assess the most appropriate skin challenge antigen to study the effect of systemic treatments on T cells. Following evaluation of the results in Cohort A, approximately 20 healthy volunteers will be enrolled in Cohort B. This cohort will be a single‐center, double‐blind, randomized, two‐arm, placebo‐controlled study to evaluate the effect of corticosteroid treatment on the molecular and cellular phenotype of delayed hypersensitivity response to one if the antigens previously studied in Cohort A.