The purpose of this study is to evaluate epidermal nerve fiber (ENF) regeneration and
normalization of peripheral sensory nerve function over time in normal healthy volunteers
following a 60 minute application of Capsaicin Dermal Patch (NGX 4010; capsaicin 640 mcg/cm2)
as compared to comparable untreated skin areas (control).The objectives of this study are: 1)
To assess the difference between patch-treated and comparable untreated skin areas (control)
in ENFD as quantified by PGP 9.5 immunohistochemical staining of skin biopsy samples obtained
at 1, 12 and 24 weeks following a 60 minute application; 2) To assess the difference between
patch-treated and comparable untreated skin areas (control) for thermal detection thresholds
as assessed by QST at 1, 12 and 24 weeks following a 60 minute application; and, 3) To assess
the difference between patch-treated and comparable untreated skin areas (control) in
mechanical (sharp pain) sensation and tactile threshold at 1, 12 and 24 weeks following a 60
minute application.