Intraepidermal nerve fiber density in vulvar lichen sclerosus and normal vulvar tissues

Lichen sclerosus (LS) is a chronic and inflammatory disease causing sensory symptoms such as itch and pain and affecting most frequently genital skin of women. Intraepidermal nerve fiber density (IENFD) was examined immunohistologically in 20 vulvar skin biopsies of patients affected by LS and in 20 control vulvar skin biopsies, in order to determine if these sensory sensations originate in changes in the epidermal innervation. Obtained results show fewer protein gene product 9.5 (PGP 9.5) positive intraepidermal nerve fibers (IENF) in LS tissues compared to controls (P = 0.004), while the number of calcitonin gene-related peptide (CGRP) positive IENF in LS was increased compared to normal vulvar tissue (P = 0.03). No differences in the number of vasoactive intestinal peptide (VIP) expressing IENF could be observed. To our best knowledge, this is the first study to describe intraepidermal nerve fiber density in vulvar LS. Significant differences in IENFD between LS and control skin samples, which have been found, point to the damage to the small nerve fibers in the disease process of LS, which may contribute to pathogenesis of LS sensory symptoms.