A, The relative increase of cytokine mRNAs (medians) is shown in log scales in comparison to their respective normal skins. By Mann-Whitney U test, mRNA increased significantly in the patch test sites over paired controls for IFN-γ (P<0.001), IL-4 (P<0.005), IL-17 (P<0.005), RORC (P<0.005), IL-17F (P < 0.05), and IL-23p19 (P < 0.005). B, Relative fold change in cytokine mRNA expression as the patch test score increases over time in one patient with nickel allergy and a crescendo patch test reaction.