739 Three-dimensional imaging and quantification of epidermal innervation in atopic dermatitis

Understanding the structural alteration of epidermal innervation is essential for a deeper understanding of neurogenic inflammation and pruritus in atopic dermatitis. The skin of atopic dermatitis patients has been reported to show controversial results, higher or lower intraepidermal nerve fiber densities (IENFDs). Therefore, this study was intended to verify the genuine structural alteration of epidermal innervation in atopic dermatitis through the skin-clearing technique and related three-dimensional (3-D) image quantification process as previously reported. A total of 10 (five healthy and five atopic dermatitis subjects) participants were prospectively enrolled. All subjects were male, 20s, and received biopsy/suction blister on a similar anatomical site, proximal forearm, to control other variables which could affect the results of IENFDs. The atopic dermatitis patients displayed significantly decreased intraepidermal nerve fibers, nodes, end, total length, total volume, and complexity compared with the results of healthy subjects. Furthermore, the arborizing intermingled structures of healthy subjects represented by nodes and complexity seemed to be more vividly simplified in the atopic dermatitis patients compared with the degree of decrease of well-known parameters, number of nerve fibers, or total length. In conclusion, our study successfully demonstrated the difference of 3-D whole structural images of epidermal innervation between healthy subjects and atopic dermatitis patients. Further studies with a larger number of participants are expected to show the possible relationship among structural alteration of epidermal innervation, neurosensory symptoms, and neurogenic inflammation of atopic dermatitis.