title: Nerve involvement in granuloma annulare.
abstract: BACKGROUND
  Nerve involvement developed in a patient with granuloma annulare, as evidenced by a perineural infiltrate of histiocytes in the dermis. The histopathologic pattern was suggestive of leprosy. No mycobacteria were observed, and neurologic testing was normal.
  
  
  OBJECTIVE
  To determine whether inflammation of the nerves or perineural tissue is common in granuloma annulare, we studied the cutaneous nerves in skin biopsy specimens from 14 patients with granuloma annulare.
  
  
  METHODS
  Sections were stained with hematoxylin-eosin to highlight inflammatory cells and with S-100 to identify cutaneous nerves.
  
  
  RESULTS
  No inflammation around nerves was found in 12 specimens, abutting granulomatous inflammation was found in 1 specimen, and enveloping granulomatous inflammation was found in 1 specimen. No nerves were infiltrated by inflammatory cells.
  
  
  CONCLUSIONS
  Perineural granulomatous inflammation resembling the perineural infiltrate of leprosy appears to be an uncommon characteristic of granuloma annulare. Clinical correlation and acid-fast stains can assist in establishing the correct diagnosis.
authors.affiliation: Department of Dermatology, Mayo Clinic, Scottsdale, AZ 85259, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Longmire
authors.forename: David J
authors.initials: DJ
authors.lastname: DiCaudo
authors.forename: Mark V
authors.initials: MV
authors.lastname: Dahl
mesh_terms: D000368:Aged; D005260:Female; D016460:Granuloma Annulare / Q000150:complications / Q000473:pathology*; D006644:Histiocytes / Q000473:pathology; D006801:Humans; D009443:Neuritis / Q000150:complications / Q000473:pathology*; D010525:Peripheral Nerves / Q000473:pathology*; D012867:Skin / Q000294:innervation