title: False-negative anti-treponemal immunohistochemistry in secondary syphilis.
abstract: BACKGROUND
  While serological studies are the primary tool used to confirm the diagnosis of secondary syphilis, skin biopsies are often performed to control for potential false positives and negatives. Immunohistochemistry using anti-T. pallidum specific antibodies has proven to have a very high sensitivity and specificity for identification of spirochetes in biopsy specimens, but can occasionally fail to identify organisms in clinically and serologically confirmed cases.
  
  
  METHODS
  We report two cases of apparently negative biopsy specimens in which rare organisms were subsequently identified by detailed study of multiple additional sections.
  
  
  RESULTS
  Our experience suggests that the sensitivity of immunohistochemistry for syphilitic spirochetes may be improved by repeat immunostaining.
authors.affiliation: Department of Dermatology, Mount Sinai School of Medicine, New York, NY 10029, USA. ingeputri@yahoo.co.uk
authors.forename: Inge
authors.initials: I
authors.lastname: Putri
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Mercer
authors.forename: Robert G
authors.initials: RG
authors.lastname: Phelps
authors.forename: Jacob O
authors.initials: JO
authors.lastname: Levitt
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000276:immunology; D001706:Biopsy; D005188:False Negative Reactions; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods / Q000592:standards*; D008297:Male; D012680:Sensitivity and Specificity; D013587:Syphilis / Q000175:diagnosis* / Q000473:pathology; D013588:Syphilis Serodiagnosis / Q000379:methods / Q000592:standards*; D014210:Treponema pallidum / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D000907:Antibodies, Bacterial