Evaluation of Five Selected Markers in Skin Biopsies of Patients With Postherpetic Neuralgia and Healthy Controls

Using a punch biopsy, the study doctor will take a small sample of skin (3mm diameter) from a pre-defined site of the subject. For PHN patients, 4 biopsies will be obtained: 2 in an area of PHN and 2 in a contralateral control site. Biopsy sites for each PHN control subject will be matched anatomically to the corresponding PHN patient with two biopsies each from symmetrical sites in a left and right dermatome. One biopsy from each site in each subject will be fixed in a left and right dermatome. One biopsy from each site in each subject will fixed yb immersion in 4% paraformaldehyde for immunocytochemical analysis, and the second biopsy form each site will be flash frozen for assessments of mRNA expression.