title: Detection of human papillomavirus infection in trichilemmomas and verrucae using in situ hybridization.
abstract: BACKGROUND
  It is hypothesized that trichilemmomas are 'burned out' verrucae. By performing in situ hybridization using HPV type-specific probes, we explored this concept.
  
  
  METHODS
  Verrucae vulgaris and plantaris were positive controls, and inverted follicular keratoses (IFKs) were negative controls. Additionally, all lesions were tested for HPV genital types (low and high risk).
  
  
  RESULTS
  We analyzed 9 trichilemmomas, 20 verrucae vulgaris, 8 verrucae plana, 3 verrucae plantaris and 6 IFKs. All trichilemmomas were negative for HPV types 1, 2 and genital types. Conversely, 9/20 verrucae vulgaris, 2 verrucae plantaris, and 1 verruca plana were positive for HPV type 2. Among HPV-2 positive lesions, 2/2 verrucae plantaris and 1 verruca vulgaris (chin) were strongly positive for genital-type HPV. One verruca plana (shin) was positive for genital-type HPV only. All 6 IFKs were HPV negative.
  
  
  CONCLUSIONS
  Using HPV type 1 and 2-specific probes and mixed genital-type probes, we were unable to detect HPV in trichilemmomas. This suggests that HPV-1, HPV-2 and low and high risk genital-type HPVs are not involved in the histogenesis of trichilemmoma. We also showed that genital HPV types could be present in non-genital verrucae.
authors.affiliation: Department of Dermatology, Wayne State University, Dearborn, MI, USA. sstierman@med.wayne.edu
authors.forename: Sarah
authors.initials: S
authors.lastname: Stierman
authors.forename: Shaoxiong
authors.initials: S
authors.lastname: Chen
authors.forename: Gerard
authors.initials: G
authors.lastname: Nuovo
authors.forename: Jean
authors.initials: J
authors.lastname: Thomas
mesh_terms: D004279:DNA, Viral / Q000032:analysis; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods; D018295:Neoplasms, Basal Cell / Q000473:pathology / Q000821:virology*; D027383:Papillomaviridae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D030361:Papillomavirus Infections / Q000473:pathology / Q000821:virology*; D012878:Skin Neoplasms / Q000473:pathology / Q000821:virology*; D014860:Warts / Q000473:pathology / Q000821:virology*
chemical_list: D004279:DNA, Viral