Cytokine protein expression by immunohistochemistry in acral samples. (a) CD3ε and IL-17 IHC (brown) and IL17A RISH (red) in serial sections of PP tissue. (b) CD3ε and IFN-γ IHC (brown) and IFNG RISH (red) in serial sections of MFPP tissue. (c) CD3ε and IL-13 IHC (brown) and IL13 RISH (red) in serial sections of HPE tissue. Representative images are shown for each case. Bar = 150 μm. Ab, antibody; HPE, hyperkeratotic palmoplantar eczema; IHC, immunohistochemistry; MFPP, mycosis fungoides palmaris et plantaris; PP, palmoplantar psoriasis; RISH, RNA in situ hybridization.