title: Demonstration by S-100 protein staining of increased numbers of nerves in the papillary dermis of patients with prurigo nodularis.
abstract: BACKGROUND
  We hypothesized that hyperplasia of papillary dermal nerves was a constant feature of prurigo nodularis.
  
  
  OBJECTIVE
  We tested this hypothesis by examining sections from 25 cases of prurigo nodularis, 25 cases of skin lesions characterized by epidermal hyperplasia without clinical pruritus, and 22 cases of clinically pruritic dermatoses with variable degrees of epidermal response for the presence of papillary dermal nerves.
  
  
  METHODS
  We used a standard immunohistochemical assay with an antibody to S-100 protein as a means of identification of nerves.
  
  
  RESULTS
  In 24 of 25 cases of prurigo nodularis, papillary dermal nerves were identified by immunostaining. Cutaneous nerves were present in 1 of 22 cases of epidermal hyperplasia with pruritus and were absent in the papillary dermis in nonpruritic cases.
  
  
  CONCLUSIONS
  We conclude that hypertrophy of cutaneous papillary dermal nerves is a relatively constant feature of prurigo nodularis. The presence of papillary dermal nerves suggests a neurocutaneous component in the pathogenesis of prurigo nodularis.
authors.affiliation: Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, FL.
authors.forename: B
authors.initials: B
authors.lastname: Harris
authors.forename: K
authors.initials: K
authors.lastname: Harris
authors.forename: N S
authors.initials: NS
authors.lastname: Penneys
mesh_terms: D006801:Humans; D007150:Immunohistochemistry; D009412:Nerve Fibers / Q000473:pathology*; D011536:Prurigo / Q000378:metabolism / Q000473:pathology; D011537:Pruritus / Q000473:pathology; D009418:S100 Proteins / Q000032:analysis*; D012867:Skin / Q000737:chemistry / Q000294:innervation*; D012871:Skin Diseases / Q000378:metabolism / Q000473:pathology*
chemical_list: D009418:S100 Proteins