Three-dimensional analysis of cutaneous nervous system in pruritic atopic dermatitis and psoriasis skin

Introduction: Intraepidermal nerve fiber (IENF) count in skin biopsies has been used as a reflection of the innervation density of itch-transmitting C nerve fibers in the skin. Changes in IENF densities in pruritic conditions such as eczema and psoriasis has been studied previously, but conflicting results have been reported. In these studies, IENF count is defined as the number of PGP9.5-positive nerve fibers crossing the basement membrane per unit length in 50-μm-thick histologic sections. However, this 2-dimensional approach is limited by the thickness of the section examined.