Myeloid dendritic cells are increased in the lesional skin and associated with pruritus in patients with prurigo nodularis.

The number of dermal mDCs (CD11c+ cells) was increased with itch intensity (r = 0.886, p = 0.003) using immunofluorescence (IF). On IF, CD11c+ mDCs expressed IL-31 in lesional PN skin. Fluorescence in situ hybridization combined with IF also confirmed IL-31 mRNA expression by mDCs in PN lesion. Higher population of colocalization of CD11c+ mDCs expressing IL-31 mRNA were more than CD68+ macrophages and CD3+ T cells in consecutive sections of PN skin lesion. HC, healthy control; PN, prurigo nodularis; SPN, PN with severe pruritus (itch NRS score ≥7 points); MPN, PN with mild pruritus (itch NRS score <3 points); NRS, Numeric Rating Scale; AD, atopic dermatitis; mDC, myeloid dendritic cell.